Transaction - Bitcoin Wiki

Thoughts on Mycelium Wallet?

Is it safe to send coins from Mycelium to DNMs or do they track like Coin Base?
submitted by Disciple2115 to darknet [link] [comments]

Which software wallet should I use, and why?

I have used Copay and Electrum. I am aware it is not possible to spend BCC directly with Electrum, but I am using this to hold coins for a long term and all I need is actually the private keys... and a trusted developer ;)
submitted by btc-newbie to btc [link] [comments]

I tested KeepKey + Mycelium + SegWit so you don't have to.

TLDR: you can send and receive Bitcoin to and from native SegWit (Bech32) addresses using KeepKey + Mycelium, but not using KeepKey + KeepKey client (yet?).
Mycelium can import the extended public key (xpub) from your KeepKey, this allows you to get a watch-only wallet on your phone, that can spend only if you connect your KeepKey to the phone. The xpub is not the private key, the private key never leaves KeepKey, you can not spend from just the xpub, cold storage is not compromised. It's a nice combination of the accessibility of an app, and the security of a hardware wallet. My favorite feature is being able to watch the value of my Bitcoin moon plummet from the comfort of my phone. The Mycelium Android wallet finally got it's SegWit update this month, and I used about a buck in Bitcoin to test the new address format.
Importing a KeepKey xpub into Mycelium
The first thing to note is that if you already had a KeepKey account in Mycelium before Mycelium's SegWit update you'll have to remove that account from Mycelium and reimport it to enable SegWit support.
To import your KeepKey’s xpub into Mycelium you need to connect the KeepKey to your phone using a USB OTG adapter, you can get one for about 10 bucks if one did not already come with your phone. When connected, open Mycelium, go to the “accounts” tab, tap the icon of a key with a “+”, tap “advanced”, tap “KeepKey”, and enter your pin.
(If you have enabled passphrase protection on your KeepKey then at this point Mycelium will also ask you to enter the passphrase now. You can read this page for instructions on how to enable/disable passphrase protection: https://help.keepkey.com/how-to-guides/how-to-disable-a-passphrase If you want to enable it change the command from “(false)” to “(true)”. This is an advanced feature so only use this if you know what you are doing, enabling and disabling it has been very flaky in my experience, but once enabled the passphrase feature itself works without error)
Accounts
Mycelium will now scan KeepKey for accounts, if you have multiple accounts on the KeepKey and want to add all of them to Mycelium you will have to go through these steps multiple times to add them one at a time. An account with zero Bitcoin will not be detected by Mycelium.
You can give the account you are adding to Mycelium a label. Mycelium will display a KeepKey logo next to the account name in the accounts tab to indicate this is a watch-only account from a KeepKey.
What can I do with an imported account in Mycelium?
Without having your KeepKey connected you can: -View your Bitcoin balance and it’s fiat value. -View all transactions including those done through the KeepKey Client app. -Generate receiving addresses in all three formats, legacy P2PKH (starting with 1), SegWit wrapped P2SH (starting with 3), SegWit native Bech32 (starting with bc1). -Receive Bitcoin on said addresses and view the incoming transactions before during and after they are confirmed. Note that Mycelium will default to generating SegWit wrapped P2SH receiving addresses, you can change the default to SegWit Native Bech32, but you can not change the default to legacy P3PKH addresses, this is important.
How do I receive Bitcoin with Mycelium?
Choose the KeepKey account from the accounts screen, tap the “receive” button and it will display a SegWit Wrapped P2SH address by default. You can switch to a Legacy or Bech32 address from this screen, and switch the default from P2SH to Bech32, but not to Legacy. This means that by default you will always be receiving Bitcoin on a SegWit address.
How do I send Bitcoin from Mycelium?
In order to send Bitcoin from Mycelium you can tap “send”, enter a receiving address, choose an amount and a fee setting. Next you will have to connect your KeepKey to the phone with the OTG adapter, enter the pin, and enter the passphrase if your KeepKey has one. The transaction will be displayed on the KeepKey’s own display, you should verify the address, amount and fee. Confirm the transaction through the physical button on the KeepKey, twice. Your transaction will be broadcast, you can now disconnect the KeepKey.
How secure is this?
The private key never leaves the KeepKey, cold storage is never compromised. The only way to sign a transaction and send Bitcoin is by connecting the KeepKey, entering the pin to unlock it, and entering the passphrase to further unlock it if you have one enabled, and then using the physical button on the KeepKey to confirm the transaction.
What does not work?
And now finally, the reason I’m making this post, what does not work. At the time of writing the KeepKey client app for Chrome is capable of sending to SegWit P2SH and Bech32 addresses. The KeepKey Client app is however not capable of generating SegWit receiving addresses, nor can it view the balance of SegWit P2SH or SegWit Bech32 addresses. It also can not send Bitcoin that was received on these addresses.
This means that if you use Mycelium to receive Bitcoin on a SegWit address, the KeepKey Client app does not understand this transaction. The KeepKey Client app will not add the balance of this address to your total balance, if this was the only transaction in the wallet it will show a zero balance. The KeepKey Client app will not be able to send Bitcoin that was received on these addresses, you can only do that using Mycelium. This can lead to confusing situations where Mycelium and the KeepKey Client app show two different total balances for the same wallet, because Mycelium sees the real balance, and the KeepKey Client app only sees the non-SegWit addresses balance.
I fully expect a future update to the KeepKey Client Chrome app to enable full SegWit support so the above will no longer be an issue, but right now receiving Bitcoin on SegWit addresses through Mycelium means you can no longer effectively use the KeepKey Client app until it is updated.
submitted by De_Wilde_Weldoener to Bitcoin [link] [comments]

I think its time we have an educated discussion what the cause and effects are of a post August 1st BIP148 world. There are some serious concerns that need to be addressed and we will not overcome these issues unless we educate ourselves and start actively coming up with solutions.

So I think that there are some misconceptions that needs to be cleared up regarding the difference between signaling intent and actual activation of SegWit.
As I understand it come August 1st there will be orphanage of blocks that do not signal SW. This means that from August 1st until November 1st(+ retarget period) when segwit is actually enforced there will be a several month period in which the transaction format stays the same yet there will be two branches of "Bitcoin" being mined both conducting transactions that are compatible across both chains with no guarantee as to which transaction will make it into which blockchain.
If there is no clean way to divide your transactions to ensure with a 100% guarantee that it will make it into bip148 chain vs legacy chain be then we will have systematic chaos. There is also a possibility of massive losses. What if your receiving funds from a legacy chain address to your wallet that gets picked up in the bip148 block but not the legacy chain and the bip148 chain dies off? That tx never happened and you lose your money. Not to mention even if we assume a best-case scenario in which every single miner currently signaling segwit mines the bip148 chain we will see blocks confirm at approximately 30 minutes vs 10 minutes. Now if we're not delusional thinkers we will accept that we will not have a maximum output of miners and instead there will be a faction that goes one way or the other leaving us with probably much less than 30% of hashrate. 1hr blocks is my best guess. We currently go sometimes 40 minutes to 1 hour with bad luck from miners with the current hashrate. That means that we may see four to six hour block confirmation times with bad luck on bip148 miners, assuming my best case guess of hashrate. Of course you have to mention that it will sometimes go the other way and we will get 5 to 10 minutes Blok confirmation times as well.
Either way the more I look at the basic assumptions of how this will play out the more cautious I am about it. In order for this to succeed it has always relied on large economic actors transacting on bip148 supporting nodes, and I don't see how this can be done without widely deployed ecological support from both wallets and exchanges.
I still support bip148 but we need solutions for replay attack protection immediately and that won't happen unless we educate developers on the present issue and make them understand that this caveat is currently a do-or-die situation.
I mentioned the issue to the mycelium developer and he said that they are essentially looking into it but gave no further information. I hope that electrum and all other wallet providers are also looking into this issue as well as exchanges, but I also fear that there is a status quo divided between wallets and exchanges.
It seems to me that according to the communications published by Major wallet developers they are all favorable to bip148, but so far exchanges have been very wary to make any public statements regarding this proposal. This makes sense because they wish to protect their customers and their Investments and that means maintaining the status quo and not encouraging something that would cause disruption and possibly large economic losses.
Unless we can get replay attack protection integrated into the proposal or broadly across the ecosystem fast then it doesn't seem that the exchanges are going to give their customers a choice on this issue.
Without their support I fail to see how this will be successful. shaolinfry stated right in the bip148 submission that economic support is a do or die scenario. I'm of the position that if we cannot rally the appropriate amount of economic support before August 1st that we should withdraw software supporting this proposal as to not ensure chaos within the network.
Honestly this reminds me a lot of the Bernie or bust movement. I liked the movement because it was a Grassroots movement that was trying to stand up to the status quo. And in order for your movement to succeed you have to approach it with a cult-like fever as to instill upon other people within the public your cultish fever towards accomplishing a goal that seems pretty obvious as to be with in the best interest of the community (SegWit). But if your movement only divides society and allows another incumbent to dominate, or even worse a new player to step in and take over the system that is even worse, then all your movement has succeeded in doing is to worsen the situation at the exact polar opposite of what you were trying to accomplish, which was to better the system.
These sociological effects are difficult to examine from a personal perspective when you're in entrenched in the ideology, but post-event you can look backwards and say "wow I really fucked up". I think that's what Bernie or bust people are unanimously saying right now, or at the very least they're thinking it inside their heads even if they don't want to admit it to all of their friends and families because they wish to save face.
Think if all the Bernie or bust crowd voted for Hilary right now? We would have a different president. And regardless of your particular political alignment this demonstrates how when you have a minority faction within a system who are cultish in their approach how they can skew the race and change the outcome. Please don't downvote me because you think I'm talking trash on your favorite politician, I am not I am merely representing the social divides and how they can change outcomes.
bip148 is that cultish social divide right now and I would like to see more discussion on the realistic outcomes that we will see after August 1st and how we will navigate these outcomes. We cannot succeed by pushing our heads in the sand and ignoring the problems that this movement currently faces, and we should be willing to shift our position if in the face of overwhelming evidence we see that this will lead to a negative and not positive outcome.
The way I see it there are solutions to these problems but with time being limited I'm not sure how realistic it is to implement these Solutions to Rally the support needed for a transition in the right direction.
Solutions for success -
1) replay attack protection 2) major exchange support (get a single one and it will snowball) 3) a compatible proposal like what Jeff garzik is working on or bip91/COOP that has compatibility with current bip148 installations.
If we cannot accomplish one and two then I do not think that we should support mining a bip148 chain. If number 3 occurs then I think it will make the situation significantly less risky if there is wide support across the ecosystem that actually installs that software. If it is installed then it is assumed that it will signal SW which would then create a majority of the ecosystem signaling SW which would be compatible with bip148 because the blocks would not be orphaned. I think it would result in a minority chain that would be quickly abandoned since miners follow the money and a non-SW signaling fork wont be of any value if say, 75%+ of the ecosystem is not only mining SW signaling blocks orphaning non SW blocks.
submitted by Cryptolution to Bitcoin [link] [comments]

I tested KeepKey + Mycelium + SegWit so you don't have to.

TLDR: you can send and receive Bitcoin to and from native SegWit (Bech32) addresses using KeepKey + Mycelium, but not using KeepKey + KeepKey client (yet?).
Mycelium can import the extended public key (xpub) from your KeepKey, this allows you to get a watch-only wallet on your phone, that can spend only if you connect your KeepKey to the phone. The xpub is not the private key, the private key never leaves KeepKey, you can not spend from just the xpub, cold storage is not compromised. It's a nice combination of the accessibility of an app, and the security of a hardware wallet. My favorite feature is being able to watch the value of my Bitcoin moon plummet from the comfort of my phone. The Mycelium Android wallet finally got it's SegWit update this month, and I used about a buck in Bitcoin to test the new address format.
Importing a KeepKey xpub into Mycelium
The first thing to note is that if you already had a KeepKey account in Mycelium before Mycelium's SegWit update you'll have to remove that account from Mycelium and reimport it to enable SegWit support.
To import your KeepKey’s xpub into Mycelium you need to connect the KeepKey to your phone using a USB OTG adapter, you can get one for about 10 bucks if one did not already come with your phone. When connected, open Mycelium, go to the “accounts” tab, tap the icon of a key with a “+”, tap “advanced”, tap “KeepKey”, and enter your pin.
(If you have enabled passphrase protection on your KeepKey then at this point Mycelium will also ask you to enter the passphrase now. You can read this page for instructions on how to enable/disable passphrase protection: https://help.keepkey.com/how-to-guides/how-to-disable-a-passphrase If you want to enable it change the command from “(false)” to “(true)”. This is an advanced feature so only use this if you know what you are doing, enabling and disabling it has been very flaky in my experience, but once enabled the passphrase feature itself works without error)
Accounts
Mycelium will now scan KeepKey for accounts, if you have multiple accounts on the KeepKey and want to add all of them to Mycelium you will have to go through these steps multiple times to add them one at a time. An account with zero Bitcoin will not be detected by Mycelium.
You can give the account you are adding to Mycelium a label. Mycelium will display a KeepKey logo next to the account name in the accounts tab to indicate this is a watch-only account from a KeepKey.
What can I do with an imported account in Mycelium?
Without having your KeepKey connected you can: -View your Bitcoin balance and it’s fiat value. -View all transactions including those done through the KeepKey Client app. -Generate receiving addresses in all three formats, legacy P2PKH (starting with 1), SegWit wrapped P2SH (starting with 3), SegWit native Bech32 (starting with bc1). -Receive Bitcoin on said addresses and view the incoming transactions before during and after they are confirmed. Note that Mycelium will default to generating SegWit wrapped P2SH receiving addresses, you can change the default to SegWit Native Bech32, but you can not change the default to legacy P3PKH addresses, this is important.
How do I receive Bitcoin with Mycelium?
Choose the KeepKey account from the accounts screen, tap the “receive” button and it will display a SegWit Wrapped P2SH address by default. You can switch to a Legacy or Bech32 address from this screen, and switch the default from P2SH to Bech32, but not to Legacy. This means that by default you will always be receiving Bitcoin on a SegWit address.
How do I send Bitcoin from Mycelium?
In order to send Bitcoin from Mycelium you can tap “send”, enter a receiving address, choose an amount and a fee setting. Next you will have to connect your KeepKey to the phone with the OTG adapter, enter the pin, and enter the passphrase if your KeepKey has one. The transaction will be displayed on the KeepKey’s own display, you should verify the address, amount and fee. Confirm the transaction through the physical button on the KeepKey, twice. Your transaction will be broadcast, you can now disconnect the KeepKey.
How secure is this?
The private key never leaves the KeepKey, cold storage is never compromised. The only way to sign a transaction and send Bitcoin is by connecting the KeepKey, entering the pin to unlock it, and entering the passphrase to further unlock it if you have one enabled, and then using the physical button on the KeepKey to confirm the transaction.
What does not work?
And now finally, the reason I’m making this post, what does not work. At the time of writing the KeepKey client app for Chrome is capable of sending to SegWit P2SH and Bech32 addresses. The KeepKey Client app is however not capable of generating SegWit receiving addresses, nor can it view the balance of SegWit P2SH or SegWit Bech32 addresses. It also can not send Bitcoin that was received on these addresses.
This means that if you use Mycelium to receive Bitcoin on a SegWit address, the KeepKey Client app does not understand this transaction. The KeepKey Client app will not add the balance of this address to your total balance, if this was the only transaction in the wallet it will show a zero balance. The KeepKey Client app will not be able to send Bitcoin that was received on these addresses, you can only do that using Mycelium. This can lead to confusing situations where Mycelium and the KeepKey Client app show two different total balances for the same wallet, because Mycelium sees the real balance, and the KeepKey Client app only sees the non-SegWit addresses balance.
I fully expect a future update to the KeepKey Client Chrome app to enable full SegWit support so the above will no longer be an issue, but right now receiving Bitcoin on SegWit addresses through Mycelium means you can no longer effectively use the KeepKey Client app until it is updated.
submitted by De_Wilde_Weldoener to keepkey [link] [comments]

Sweeping BTC,BCH,BTG from old BIP38 paper wallets into Ledger Nano S

My notes on "sweeping" BTC, BCH, and BTG from very old BIP38 protected paper wallets into Ledger Nano S:
Details:
BTC in wallet stored since 2015, so it has the BCH (Bitcoin Cash) and BTG (Bitcoin Gold) forked coins.
BTC coins in paper wallets protected with BIP38.
Old-fashioned paper wallets: Single address (Not HD). Not SegWit. Not multisig.
Using a brand new Ledger Nano S. Bitcoin wallet in "Legacy mode. Bitcoin Cash wallet in "Split" mode. Bitcoin Gold wallet in "Legacy" mode. (I just wanted to avoid any complications from SegWit. It may have been perfectly safe to use it, but I did not want to risk it potentially complicating things.)
I wanted to move these coins to my Ledger Nano S.
  1. Moving the BTC:
Use the Mycelium (Android) "Cold Storage Spending" feature to move the BTC to Ledger. This part was painless. Wait 6 confirmations before going to next step.
  1. Moving the BCH:
Use the Coinomi (Android) app's "BitcoinCash" wallet to sweep my paper wallet's BCH.
After confirmation, I then wanted to send the Bitcoin Cash from Coinomi's wallet to the Ledger. This is where I encountered my first problem. When I would QR scan the receive address from the Ledger Chrome app, Coinomi would think I was trying to send to a BTC address instead of BCH and tried to do digital currency conversion which resulted in error messages about going over the maximum limit, etc.
I finally figured out it wasn't recognizing the Bitcoin Cash address being displayed in the Chrome app as a Bitcoin Cash address.
To work-around this, I had to use another Android app, QR scanner, to read the QR code from Ledger, copy the result to the clipboard (it was "bitcoin:1XXXXX"), modify the text to "bitcoincash:1XXXXX") and then paste the modified text into the Coinomi send-to address. Always double check every character of the address to prevent errors from typos (dropping characters, etc.) or clipboard interception malware.
  1. Moving the BTG:
The Bitcoin Gold sweep proved even more challenging. Switch to the "BitcoinGold" wallet in Coinomi.
Coinomi could not sweep the wallet using the QR scan of the BIP38 private key like it did for Bitcoin Cash, it just gives a "The private key type does not match the destination account type" error message.
Instead, from my laptop, I had to go to bitaddress.org, click on "Wallet Details", DISCONNECT YOUR MACHINE FROM THE INTERNET, and then paste the BIP38 private key into the "Enter Private Key" field. Click "View Details", and it will then ask you to type in your BIP38 secret passphrase. Do that and a bunch of private key WIF format QR codes will appear.
The Coinomi support page says to use sweep using the "Private WID Compressed key... starts with a 'K' or 'L' code", but this did not work for me (would only show me an "The address has no funds" error message). Instead, I had to sweep using the "Private Key WIF" starting with a '5' for it to work.
The BTG sweep instructions are generally from: https://coinomi.freshdesk.com/support/solutions/articles/29000017747-i-can-t-sweep-my-btg-private-key except that I modified step #6 (using the '5' WIF key, not the 'K'/'L' WIF key).
Once the sweep starts in the Coinomi app on Android, CLOSE THE bitaddress.org BROWSER WINDOW in your laptop's web browser, and then re-connect to the Internet.
After you get some confirmations, then you can send directly to the BTG address in the Ledger wallet.
Be safe:
For all the wallets you swept, don't ever use those private keys or BIP38 pass phrases again. After entering the keys and passphrases in multiple places for this task to split everything up, it's possible you may have accidentally leaked the keys somewhere, so just assume the keys are burnt from now on.
Hopefully this helps people. It took me all day trying different things until I finally found a combination of steps that worked. I guess there aren't many people with BTC from years ago still on BIP38 cold storage wallets.
submitted by bjguill to ledgerwallet [link] [comments]

'What's wrong with my current cold storage method?' - an examination of potential weaknesses in the most common cold storage methods

Today we are going to discuss cold storage and some specific problems with cold storage. While this applies directly to the Secret Key portion of a key-pair; it also applies to the seed used to back up HD wallets and hardware wallets.
The best way to keep you seed/secret key safe is to have multiple copies in multiple locations perhaps with multiple formats and even better if the keys are split. However not everyone has access to multiple locations, or access to land long term, or more than one place to store their things. This is an examination of faults with individual methods; and not a comprehensive plan, obviously.
Not to say everything is all bad but there are many potential weakness out there, and some in the Bitcoin and crypto community like to know the edge cases of things.
I will also highlight some of the aspects of the Keyois Capsule which is a 'physical bitcoin'.
A physical Bitcoin is a cryptographic key pair, a physical key printed and affixed to what has always been before a coin. The first physical bitcoin coin was the Casascius coin, since then the world of physical bitcoin coins has blossomed as a fun part of the Bitcoin world.
We will focus on mediums relating to cold storage and not ones designed for more everyday use, but this applies to the seed you save to keep your everyday spending wallets safe and backed up.
We will assume you generated your keys securely and that you already have them on some medium. We will also have to ignore endpoint physical security because they can all be carried away the same. Remember your cell phone /hardware wallet/ computer client are only as good as where you put the backup seed phrase, which can be thought of as data much like the SK discussed below.
Written on a piece of paper
Printed on a piece of paper
On laminated paper
Engraved / etched/ ablated/ stamped on a piece of metal
Stored digitally on a computer
Stored digitally on CD, floppy disk, laserdisc, or mini-disc
Stored digitally on a flash drive
Backups are essential for digital data Computer code for performing operations can be corrupted in transfer or in operation. Special systems exist and procedures help data to last longer. For ideas, see this archive.gov page Remember to store in multiple locations. You can lose everything in single structure
A physical bitcoin coin
**What can solve most of these problems? A combination of good backup procedures and encryption. **
If you have permeant access to more than one location (people who live in big cities, without family or cars have a hard time with this) or have people you trust with your money (don't) then look into using some form of Multi-signature option.
The Keyois Capsule is a crypto piggy bank; it can be funded from the outside but you to break it open to get them out. You give me a BIP38 encrypted key pair (well the address not the public key) and I engrave it in this tamper evident and time resistant package. You still have to hold on to the pass phrase that allows you to decrypt it; that is however the same problem as all methods with BIP38 encryption. How to store this without having to trust anyone but still being assured of it's security?
  • Engraving, embossing, or stamping on a sheet of metal is one option; however the metals that are easiest to stamp are ones that melt in a house fire. They could be put in a glass jar that's filled with aerogel and buried. These is the best readily available option for most people but it really can be tedious. - This puts you back at anyone who can see it can steal it so dip in plastic dip, wrap in duct tape, bake in clay, encase in concrete, whatever just don't leave unencrypted keys visible!
  • The cryptosteel is another ready-made option
  • Have the words etched onto glass at home with off the shelf products; but be carful of this idea because the glass can shatter from impact and heat or even sudden temperature changes
  • Anodize the words yourself on a pieces of metal, there used to be a service to help use your home printer to print the words with some chemicals you can buy
  • Bake them in clay, then encase that in epoxy resin so it can't shatter. then paint the outside, in the future you can solvent the paint off and see the written seed
  • Use a combination of techniques to split the seed so that it is safe(because split and separated) and redundant (because backed up).
The most cost effective way for a 'normal' person (without their own land, without more than one location, and who cannot trust anyone else with their funds) to keep their backup seed/ secret key safe from damage from the elements would probably to buy a stamping kit and hammer and some stainless steel sheet or bar, Aluminium can be okay if you have the right alloy but better safe than sorry.
submitted by ProfBitcoin to Bitcoin [link] [comments]

'What is wrong with my current cold storage method' - an examination of potential weaknesses in the most common cold storage methods

Today we are going to discuss cold storage and some specific problems with cold storage. While this applies directly to the Secret Key portion of a key-pair; it also applies to the seed used to back up HD wallets and hardware wallets.
Not to say everything is all bad but there are many potential weakness out there, and some in the Bitcoin and crypto community like to know the edge cases of things.
I will also highlight some of the aspects of the Keyois Capsule which is a 'physical bitcoin'.
A physical Bitcoin is a cryptographic key pair, a physical key printed and affixed to what has always been before a coin. The first physical bitcoin coin was the Casascius coin, since then the world of physical bitcoin coins has blossomed as a fun part of the Bitcoin world.
We will focus on mediums relating to cold storage and not ones designed for more everyday use, but this applies to the seed you save to keep your everyday spending wallets safe and backed up.
We will assume you generated your keys securely and that you already have them on some medium. We will also have to ignore endpoint physical security because they can all be carried away the same. Remember your cell phone /hardware wallet/ computer client are only as good as where you put the backup seed phrase, which can be thought of as data much like the SK discussed below.
Written on a piece of paper
Printed on a piece of paper
On laminated paper
Engraved / etched/ ablated/ stamped on a piece of metal
Stored digitally on a computer
Stored digitally on CD, floppy disk, laserdisc, or mini-disc
Stored digitally on a flash drive
Backups are essential for digital data Computer code for performing operations can be corrupted in transfer or in operation. Special systems exist and procedures help data to last longer. For ideas, see this archive.gov page Remember to store in multiple locations. You can lose everything in single structure
A physical bitcoin coin
What can solve most of these problems? A combination of good backup procedures and encryption.
If you have permeant access to more than one location (people who live in big cities, without family or cars have a hard time with this) or have people you trust with your money (don't) then look into using some form of Multi-signature option.
The Keyois Capsule is a crypto piggy bank; it can be funded from the outside but you to break it open to get them out. You give me a BIP38 encrypted key pair (well the address not the public key) and I engrave it in this tamper evident and time resistant package. You still have to hold on to the pass phrase that allows you to decrypt it; that is however the same problem as all methods with BIP38 encryption. How to store this without having to trust anyone but still being assured of it's security?
  • Engraving, embossing, or stamping on a sheet of metal is one option; however the metals that are easiest to stamp are ones that melt in a house fire. They could be put in a glass jar that's filled with aerogel and buried. These is the best readily available option for most people but it really can be tedious.
  • The cryptosteel is another ready-made option
  • Have the words etched onto glass at home with off the shelf products; but be carful of this idea because the glass can shatter from impact and heat or even sudden temperature changes
  • Anodize the words yourself on a pieces of metal, there used to be a service to help use your home printer to print the words with some chemicals you can buy
  • Bake them in clay, then encase that in epoxy resin so it can't shatter. then paint the outside, in the future you can solvent the paint off and see the written seed
  • Use a combination of techniques to split the seed so that it is safe(because split and separated) and redundant (because backed up).
Characters stamped on Aluminium is probably the most cost effective way to keep a secret key or seed safe from fire and rot.
submitted by ProfBitcoin to btc [link] [comments]

I need some help reformatting a bip39 private key to bip38, WIF, or Mini private key.

I have a mycelium wallet which uses bip39. I sent my bitcoins from there to a ledger, now I would like to reformat my bip39 private keys (seed) to bip38, WIF (whatever that is) or a Mini private key because I'm trying to sweep a bgold wallet in Coinomi and that is all it accepts. I have iancoleman.github open, but it does not appear it will reformat to one of the accepted forms. I tried bip32 tab on iancoleman.github, then a table of public, private keyes and their respective paths appeared and I copy/pasted each private keyes into coinomi to the effect of it telling me there are no funds in that address. But alas, it's not bip38, it's bip32. This is a greater improvement fro. It telling me it can't read the format as it was before I used Iancoleman. I don't really know what to do here. Please advise on THIS matter.
submitted by elfof4sky to Bitcoin [link] [comments]

Does Shapeshift not accept Copay adresses for Bitcoin Cash?

EDIT: Solved it with this tool: https://bitpay.github.io/address-translato
But this sucks big time!
I try to send ETH and get BCH from Shapeshift.io. But I get this general error message everytime I try:
"There was an error creating your order, please try again in a few minutes."
(I also tried to mess with the address by removing the last letter, and get the same message. So I get this general error message when the address is wrong.)
I noticed that the BCH address generated by Copay looks weired. It starts with "CSfWap..."
I also read somwhere that BitPay (who make Copay) are making their own Bitcoin Cash address format, or something along those lines.
What is going on here? Do I have to use another Bitcoin Cash wallet app for my Android phone to receive BCH from Shapeshift?
BTC.COM wallet asks for my email, don't want that. Upgraded my Jaxx wallet. Still no BCH support. I think Bitcoin.com's wallet is based on Copay, but haven't tried it yet. No BCH support in Mycelium.
submitted by BitcoinPrepper to btc [link] [comments]

Subreddit Stats: btc top posts from 2018-04-20 to 2018-05-20 06:58 PDT

Period: 29.85 days
Submissions Comments
Total 1000 53623
Rate (per day) 33.50 1780.26
Unique Redditors 466 5134
Combined Score 118969 219877

Top Submitters' Top Submissions

  1. 7839 points, 57 submissions: MemoryDealers
    1. If all the 32MB blocks were permanently 100% full, this $400 hard drive could store the blockchain for the next 7 years. (373 points, 352 comments)
    2. The people behind Bitcoin Cash are the ones who created Bitcoin's network effect in the first place. (357 points, 123 comments)
    3. Bitcoin subscribers are now calling for people to report Bitcoin.com to the Internet Crime Complaint Center of the FBI. It's sad that BTC supporters all seem to be statists who yell about hodling their muh store of value all day. (348 points, 288 comments)
    4. I have more emails saved on my computer than the entire BTC or BCH block chains. (319 points, 131 comments)
    5. Bitcoin.com is now sponsoring pro female MMA athletes. (293 points, 121 comments)
    6. CoinGeek will support Bitcoin.com in lawsuit over the real Bitcoin - Coingeek (273 points, 354 comments)
    7. Bitcoin Cash is now on iOS in the world’s most popular crypto wallet. #winning (257 points, 131 comments)
    8. "The vast majority of mining hash power was controlled by people who were psychologically incapable of disobedience to perceived authority." -Mike Hearn (250 points, 194 comments)
    9. "BTC True Believers" Are Boycotting the First National Talk Radio Show that ever Discussed Bitcoin because they accept BCH payments. (245 points, 116 comments)
    10. All I keep hearing is that Bitcoin Cash is an infested cesspool of lawless, leaderless, disrespectful, narcissistic, greedy, scammy, capitalistic anarchists that will never create digital money! I swear I’m getting dejavu! (225 points, 46 comments)
  2. 3965 points, 19 submissions: hunk_quark
    1. Warren Buffet's Berkshire is the single largest stockholder in BoA and WellsFargo. In case you were wondering about his attitude towards Bitcoin. (614 points, 114 comments)
    2. Purse.io is paying its employees in Bitcoin Cash. (447 points, 63 comments)
    3. Shoutout to Kraken for standing up to NY Attorney General. If Schneiderman wants transparency and accountability he should be looking into auditing the fed. (406 points, 28 comments)
    4. Bitcoin is rat poison. The bankers are the rats. (404 points, 56 comments)
    5. Forbes Author Frances Coppola takes blockstream to task. (364 points, 35 comments)
    6. Purse CEO Andrew Lee confirms they are paying employees in BCH and native BCH integration update will be coming soon! (343 points, 43 comments)
    7. PSA: So called 'low-fee' cryptocurrency Litecoin has transaction fees 20x higher than Bitcoin Cash (264 points, 80 comments)
    8. After today's BCH Upgrade, longer posts are now enabled on memo.cash! (250 points, 31 comments)
    9. Jeffrey Tucker is promoting bitcoin.com at Atlanta Bitcoin Embassy. (195 points, 57 comments)
    10. Anti-Bitcoiners, life comes at you fast! (109 points, 26 comments)
  3. 3846 points, 30 submissions: Kain_niaK
    1. Bitcoin Cash has not only removed the cap on transactions but also the cap on development. Something new pops up every time I blink. (368 points, 162 comments)
    2. I am getting flashbacks from when I tried to close my Bank of America account ... (353 points, 155 comments)
    3. Fucking /bitcoin assholes reported my twitter account and now I need to verify with a phone number before I can continue with twitter. (325 points, 218 comments)
    4. Paul Wasensteiner: When is @Twitter going to fix the abuse of the report button by @bitcoincoreorg supporters? Why are supporters of a supposedly censorship-resistant money using censorship at every opportunity? (295 points, 106 comments)
    5. We should pirate the entire piratebay.org website and all it's functionality directly on to the Bitcoin Cash blockchain. The piratebay.org is just magnet links and comments. Then they will say bcash stole our business ... (232 points, 439 comments)
    6. Fees higher than a dollar cent or waiting times longer than a couple of seconds defeat the entire purpose of why Bitcoin was invented. (218 points, 164 comments)
    7. moneybutton.com is a configurable client-side Bitcoin Cash (BCH) wallet in an iframe. When the user makes a payment, a webhook URL is called allowing your app to respond to the payment, such as displaying content behind a pay wall. (189 points, 37 comments)
    8. We proudly present BCHpizza.org! Now the community can create city bounties for pizza shops to incentivize them to accept Bitcoin Cash. First pizza shop in a city to do so gets the bounty! (177 points, 117 comments)
    9. Bitcoin Cash can turn in to the biggest non violent protest against the establishment ever : "We simply stop using their money." Which is a great way of getting edgy teenagers to join us. There is an almost infinite supply of edgy teenagers in the world. (156 points, 42 comments)
    10. We need testers for the Cash Shuffle plugin. (121 points, 17 comments)
  4. 3666 points, 28 submissions: Windowly
    1. "Billion-dollar corporations take note: Bitcoin Cash is open for business! Just try to fill up our blocks, I dare you. There will be no "Fidelity Effect" with BCH. Unlike BTC, we want you to use the Blockchain. BCH never really hits a scale ceiling."~Dr. Peter Rizun (415 points, 177 comments)
    2. "In a discussion group of BCH, lots of investors concerned about the address confusing problem. BCH community should push every software of ecosystem to upgrade to Cashaddr ASAP."~Jihan Wu (366 points, 215 comments)
    3. "Maybe the best way to bring economic freedom to the world is to make an uncensorable Twitter."~Ryan X. Charles (300 points, 114 comments)
    4. Newbie tip! Do yourself a favor, get a Protonmail email account and switch all your crypto exchanges to that email. No reason Google/Gmail need to have your entire crypto history at their fingertips. (299 points, 133 comments)
    5. "On the 15th of May, I'll be popping the champagne, not to celebrate high fees, but to celebrate continued low fees, privacy enablements, smart contract capabilities, and PayPal level throughput capability."~Eli Afram (233 points, 46 comments)
    6. 24% of the trading on GDAX in the last 24 hours was for Bitcoin Cash (BCH)! 😊💃 (185 points, 16 comments)
    7. Yeah!! "We are pleased to announce that the new Bitcoin Cash address format has been implemented on QuadrigaCX. This will help our users to easily distinguish Bitcoin and Bitcoin Cash addresses when funding/withdrawing their account. The BCH legacy addresses will still be supported." (165 points, 8 comments)
    8. ANNOUNCE: Coinbase has blocked the official @WikiLeaks shop from its platform without notice or explanation. You can continue to donate #Bitcoin to WikiLeaks at https://WikiLeaks.org/donate . (164 points, 55 comments)
    9. There is a Bitcoin Unlimited election today. (BU is one of the 6+ development teams that develop clients for Bitcoin Cash (BCH). BU has a unique governance system where developers are not king. . instead members vote on proposals. If you are a member, please vote! (161 points, 29 comments)
    10. Bitpay Adds Bitcoin Cash Support to Checkout Point-of-Sale App - Bitcoin News (151 points, 22 comments)
  5. 2565 points, 15 submissions: BitcoinXio
    1. Bitcoin Cash is upgrading on May 15 to 32MB max block limit (575 points, 335 comments)
    2. Frances Coppola on Twitter: “Congratulations, Blockstream, you have just reinvented the interbank lending market.” (411 points, 139 comments)
    3. Once again Core supporters threaten with lawsuits and government intervention to try to get their way. This is just pathetic and not the foundations of what Bitcoin was built on. These are not bitcoiners. (299 points, 355 comments)
    4. Get ready - Bitcoin Cash is upgrading on May 15th! (198 points, 132 comments)
    5. CobraBitcoin: "Lightning is cool, but nobody should be recommending it to actual merchants for at least the next few years. Merchants like Steam already got hurt by adopting Bitcoin and regretting it later. Lightning needs time to mature and prove itself. Mad hype to rush adoption will harm it." (157 points, 58 comments)
    6. Blockchain on Twitter: “What's that you see? It's all your BCH that now appears in your #ios wallet. Take control of your financial future and #beyourownbank today.” (138 points, 20 comments)
    7. We are living in the digital age of information, which is why censorship has become such an important issue [...] That’s why I’m excited about decentralized social networks built on top of Bitcoin Cash like @BlockPressApp & @memobch. They are new so need work, but the path is being paved. (131 points, 31 comments)
    8. BlockPress published its protocol (123 points, 22 comments)
    9. We have a new alternative public mod logs (96 points, 35 comments)
    10. If Bitcoin Core (BTC) is no longer usable by many people in the world due to being out priced (high tx fees), is it still “borderless”? I’d argue that it’s no longer borderless if people all over the world are excluded from the network. (95 points, 34 comments)
  6. 2030 points, 11 submissions: tralxz
    1. Breaking News: Winklevoss Brothers Bitcoin Exchange Adds Bitcoin Cash support! (508 points, 115 comments)
    2. Jihan Wu was asked "Why are the miners still supporting Bitcoin Core? Is it just a short term profitability play?", he answered: "Yes, exactly." (279 points, 215 comments)
    3. Cobra:"That feeling when Blockstream, [...] release Liquid, a completely centralized sidechain run only by trusted nodes and designed for banks, financial institutions and exchanges." (245 points, 145 comments)
    4. LibreOffice Foundation accepts Bitcoin Cash donations. (191 points, 11 comments)
    5. Breaking News! Vin Armani: "Major mining pools have agreed to establish a treasury and start funding $BCH development from their block rewards. HUGE!!!" (186 points, 80 comments)
    6. CNBC's Fast Money: Ran NeuNer says he would HODL Bitcoin Cash and sell Bitcoin Core. (172 points, 59 comments)
    7. Jihan Wu on Bloomberg predicting Bitcoin Cash at $100,000 USD in 5 years. (172 points, 65 comments)
    8. Let's start the Bitcoin Cash upgrade party. New era for BCH is coming May 15. Privacy tools + smart contracts + PayPal capacity handling. Exciting times ahead! (106 points, 37 comments)
    9. Coindesk: "Florida Tax Collector to Accept Bitcoin, Bitcoin Cash Payments" (60 points, 8 comments)
    10. Adam B.: "Bitcoin is not a democracy". The authoritarian moves by Core makes perfect sense now. (59 points, 46 comments)
  7. 1485 points, 12 submissions: jonald_fyookball
    1. BTCers fundraise for frivolous lawsuit. BCH fundraises to feed Venezuelans. (233 points, 58 comments)
    2. bitcoin admits: best way to use Lightning Network: don't use it. (189 points, 286 comments)
    3. Electron Cash 3.2 is available. Includes new op-codes and fixes for Ledger hardware wallet (180 points, 50 comments)
    4. If you have to call it bcash you've already lost the argument (164 points, 257 comments)
    5. Cash Shuffle plugin 0.2 - Cash Shuffle development continues (131 points, 37 comments)
    6. Claims that BCH is a "centralized coin" are exaggerations at best. (114 points, 83 comments)
    7. (shitpost) philosoraptor meme: if honeybadger don't care... (106 points, 22 comments)
    8. BCH being a minority chain may be a blessing in disguise (97 points, 83 comments)
    9. Another reason to be bullish on BCH (92 points, 18 comments)
    10. BCHpizza already has 4 bounties posted. It's also no longer needed to sign a message to post a bounty. (89 points, 21 comments)
  8. 1393 points, 8 submissions: rdar1999
    1. Naomi Brockwell on Twitter: "[I] won’t succumb to censorship through intimidation." (332 points, 190 comments)
    2. Consensus 2018 sucked hard. Superficial talks, ridiculous ticket price, overcrowded venue. (233 points, 78 comments)
    3. ==> Becash or Begone: reclaiming the "bcash" trolling (213 points, 107 comments)
    4. See in this twitter thread Luke Jr actually arguing that PayPal is cheaper than BCH!! Is this guy in full delirium? Or just spouts misinformation on purpose? (172 points, 227 comments)
    5. ///\ BTC-BCH persists as the most popular trade on ShapeShift.io /// (171 points, 20 comments)
    6. The retard tribalism is so real. SBI japan's financial giant says they will launch a platform with BCH as settlement coin (due to BTC being bad) and XRP as remittances. I provide the link and cryptocurrency shills deny plain literally declared fact. (124 points, 50 comments)
    7. Chris DeRose on Twitter: "So if Roger ver wins the class action lawsuit, I assume that Bitcoin cash can then rightfully sue Bitcoin core proponents for fraud?" (92 points, 61 comments)
    8. Upgrade completed at height 530356! (56 points, 2 comments)
  9. 1377 points, 12 submissions: Egon_1
    1. Genesis Mining:"We are more than happy to announce that Bitcoin Cash is now available as a Native Mining option for all Bitcoin (Sha256) contracts!" (287 points, 22 comments)
    2. Jihan Wu on BCH Lighthouse:”This project was abandoned on BTC Blockchain long time ago, it is very excited to see it is alive again on BCH Blockchain. It can be very huge.” (278 points, 50 comments)
    3. Yahoo Finance: "Bitcoin Goes Lateral as Bitcoin Cash Steals the Show… AGAIN" (189 points, 46 comments)
    4. "Bitcoin Cash is actually more interesting ..." (119 points, 15 comments)
    5. Jeff Garzik:"Just got an earful from a Chicago cabbie, on $LTC He was very grumpy at @SatoshiLite selling, saying it indicated a lack of founder's confidence in his own creation. #StreetCrypto" (100 points, 8 comments)
    6. “Why don't we start saying: "Bitcoin is Cash" It's much harder to refute than "Bitcoin Cash IS Bitcoin"“ (75 points, 49 comments)
    7. "Because Bitcoin Cash is effectively Bitcoin ✌️ (72 points, 22 comments)
    8. Bye Bye P2P Electronic Cash ... (68 points, 88 comments)
    9. Bitcoin.com Wallet needs more useful services integrated... beyond Shapeshift (59 points, 24 comments)
    10. BCH keeps bitcoins minions busy (48 points, 28 comments)
  10. 1291 points, 9 submissions: increaseblocks
    1. Vitalik Buterin says what we've all been saying - CoinDesk is scammy and complicit bad actor in the cryptocurrency world and should be shunned (510 points, 61 comments)
    2. Bitcoin Wallet Mycelium Begins Rolling Out Bitcoin Cash BCH Support (163 points, 39 comments)
    3. Cheddr is a Bitcoin Cash Point Of Sale system that runs in most modern browsers - no server infrastructure required (137 points, 31 comments)
    4. Leaked Telegram chat shows bitcoin.com "fraud" lawsuit was abandoned due to lack of support 😂😂😂 (135 points, 32 comments)
    5. Toshi to expand beyond Ethereum - will add Bitcoin Cash (91 points, 7 comments)
    6. Litecoin transaction fees 20 times higher than Bitcoin Cash (85 points, 44 comments)
    7. DAMN BCH! (68 points, 25 comments)
    8. In honor of the Bitcoin Cash successful upgrade and now we have the true lightning network. I present to you lightningnetwork.cash! (58 points, 22 comments)
    9. Bcore shills are crying right now 😭😭😂😂 (44 points, 10 comments)
  11. 1202 points, 9 submissions: SharkLaserrrrr
    1. Memo is now open source! (361 points, 160 comments)
    2. Based on @BitcoinCashFund report, preliminary calculation: Total spent: $153,138.49 Total spent on Salaries and Travel: $101,996.79 ~66% of donations is spent on themselves, charities/non-profits (official registered ones) limit themselves to less than 10% (161 points, 181 comments)
    3. [PREVIEW] Looks like Lighthouse powered by Bitcoin Cash is coming together nicely thanks to the hard work of an anonymous developer. I wonder how Mike Hearn feels about his project being resurrected. (159 points, 24 comments)
    4. We heard you want a Bitcoin Cash exclusive wallet that uses ‘bits’ and enables you to buy anything online and pay with Bitcoin Cash so we are building one #cashpay #CryptonizeYourPurchases (137 points, 77 comments)
    5. Bitcoin Cash is the real Bitcoin experience. If you have any doubts, go buy something on cryptonize.it, then buy something off a Lightning store and compare what you had to go through to pay for your order. (103 points, 51 comments)
    6. As of today, cryptonize.it shows prices in Bitcoin Cash next to fiat! (81 points, 9 comments)
    7. Incompatible protocols gave us the ’90s web which was not a pretty sight. Let’s not repeat the same mistakes when building censorship resisted social media powered by Bitcoin Cash. Support @MemoBCH protocol. (72 points, 57 comments)
    8. To help developers raise funds, cryptonize.it is sponsoring a Lighthouse server and website so useful projects can be funded by the community directly. (66 points, 7 comments)
    9. $25,- Amazon gift cards back in store, 0-conf. instant delivery, the real bitcoin experience (62 points, 18 comments)
  12. 1189 points, 1 submission: ocist1121
    1. No spend (1189 points, 87 comments)
  13. 1148 points, 6 submissions: BeijingBitcoins
    1. Three years ago today, Mike Hearn published an article explaining exactly what would happen when the 1MB blocksize limit was hit. He was right on all counts. (473 points, 173 comments)
    2. An easy way to visualize the August 1st Hard Fork. Neither of the two branches resulting from a fork can be called "the original road," but only one branch continues towards the same destination. (163 points, 140 comments)
    3. Bitcoin Core fanatics are trying to organize a lawsuit against Bitcoin.com for using the term "Bitcoin (BCH)", while they run around all day labelling it "Bcash" (157 points, 167 comments)
    4. "Bitcoin Cash won't "fork" in May. Instead, Bitcoin Cash will just upgrade." (123 points, 53 comments)
    5. Just launched: Satoshi Pulse, by Bitcoin.com (121 points, 44 comments)
    6. Ryan Charles delivers an epic rant about Lightning Network problems (111 points, 19 comments)
  14. 1085 points, 10 submissions: unitedstatian
    1. Reminder: Blockstream plans to make money from the proprietary solutions it sells, which is why it moved away from the free permissionless blockchain to an abstracted layer on top which requires 3rd party solutions to be cost effective for most users. (220 points, 146 comments)
    2. It seems there's been a massive propaganda campaign to brainwash people into thinking hardforks are bad. (180 points, 56 comments)
    3. BCH could really be missing the new big use case. Gamers would love to have real ownership of game items. The first game which will integrate a digital coin and make it popular will be groundbreaking. (141 points, 76 comments)
    4. The guy had 350 bucks received via Lightning Network but he can't even close the channels to actually withdraw the bitcoins. (139 points, 188 comments)
    5. What gives Core the right to change the model so drastically and still keep the brand name? (119 points, 117 comments)
    6. One of the most ignorant - even anti-crypto - argument I hear around is that BCH is a currency controlled by Chinese miners. (88 points, 74 comments)
    7. The first megabytes are far more crucial than the 100th. Not every MB was born equal and by giving up on adoption for years Core may have given up on adoption forever. (69 points, 20 comments)
    8. In light of the recent ERC-20 bug I think this is a good time to remember these wise words (54 points, 25 comments)
    9. If BCH had decent privacy features it'd gain so much more market share. It's hard to compete with privacy-always-on coins such as XMR but many more coins offer moderate privacy and would be easy to beat. (42 points, 31 comments)
    10. If Memo taught me one thing it's the more uses around the coin the better - can BCH be adopted to help fight counterfeiting? (33 points, 4 comments)
  15. 1055 points, 5 submissions: ForkiusMaximus
    1. MortuusBestia hits on a pitch-perfect way of looking at BCH's value proposition in epic comment on /BitcoinMarkets (604 points, 109 comments)
    2. I am excited that BCH is being irrationally criticized, because it reminds me of 2011 and 2012 when Bitcoin was being irrationally criticized. Any of 2013, when the price rose 100x. (183 points, 82 comments)
    3. Japanese tweeter makes a good point about BTC: "You don't call it an asset if it crumbles away every time you go to use it. You call it a consumable." (144 points, 21 comments)
    4. Jimmy Nguyen: Bitcoin Cash can function for higher level technical programming (80 points, 3 comments)
    5. How NOT to tell which is "the real Bitcoin" (44 points, 15 comments)
  16. 1032 points, 6 submissions: theantnest
    1. Let's start a class action lawsuit against Canada for calling their currency the dollar. I accidentally bought CAD when I wanted USD, and didn't know I could just exchange it again. (511 points, 243 comments)
    2. BTC noobs conned into being concerned about node count to distract them from the real centralization problem: (137 points, 172 comments)
    3. Any real scientist interested in Bitcoin should be happy Bitcoin Cash exists. (110 points, 40 comments)
    4. Blockstream shill admits to exaggerating and slandering Roger purely because he doesn't support BTC. (103 points, 49 comments)
    5. Cognitive Dissonance: It's totally fine to call BCH 'bcash', but it's fraudulent to call it Bitcoin? (93 points, 51 comments)
    6. Be Cash! (78 points, 45 comments)
  17. 1029 points, 7 submissions: zhell_
    1. MEMO NOW SUPPORTS REPLIES, join the Party now ! (208 points, 50 comments)
    2. memo.cash has been generating 2000 tx/day since its start, which is near 10% of all transactions on the BCH network. (201 points, 73 comments)
    3. "Money comes from being the most tradable of all commodities" Austrian Economics (189 points, 104 comments)
    4. Fiat is crashing: Inflation in the US averages at 10%/year in the past 5 years when measured as the price of the top 500 items on which Americans spend their after-tax dollars. (183 points, 49 comments)
    5. Memo.cash breaks a record with 3000 on-chain actions in the last 24h after implementing replies (143 points, 25 comments)
    6. with 2k tx/day, memo.cash is only using ~0.09% of 8MB blocks capacity currently on the BCH network (that would be 0.02% of 32MB blocks) (69 points, 3 comments)
    7. Help! I bought what I thought was Bitcoin and it is now gone! /s (36 points, 8 comments)
  18. 1020 points, 4 submissions: Anenome5
    1. Let's End the War and focus on the TRUE ENEMY (719 points, 349 comments)
    2. Satoshi's original whitepaper talks about "Reclaiming Disk Space" by pruning transactions, what's being done on this front? Core-trolls say we don't need to store forever that you bought a coffee, and that's true, and Satoshi also proposed how to fix that long ago. (200 points, 166 comments)
    3. Core'er says $50 fees "a wtf moment for everyone" but doubts it will ever happen again. Seems they're in for a surprise, BTC is still extremely vulnerable to transaction-fee price-inflation due to low capacity. BTC transaction fees currently 19+ times higher than BCH. (65 points, 30 comments)
    4. Bitcoin Cash, the early years... [OC] (36 points, 16 comments)

Top Commenters

  1. jessquit (3904 points, 368 comments)
  2. Kain_niaK (3058 points, 684 comments)
  3. bambarasta (2674 points, 360 comments)
  4. H0dl (2352 points, 464 comments)
  5. rdar1999 (2352 points, 404 comments)
  6. BitttBurger (2301 points, 313 comments)
  7. Adrian-X (2118 points, 506 comments)
  8. MemoryDealers (2084 points, 102 comments)
  9. trolldetectr (2073 points, 502 comments)
  10. LexGrom (2055 points, 709 comments)
  11. Ant-n (1834 points, 334 comments)
  12. LovelyDay (1820 points, 468 comments)
  13. jimbtc (1734 points, 212 comments)
  14. fruitsofknowledge (1618 points, 469 comments)
  15. ForkiusMaximus (1612 points, 211 comments)
  16. unstoppable-cash (1537 points, 201 comments)
  17. unitedstatian (1485 points, 388 comments)
  18. jonald_fyookball (1481 points, 142 comments)
  19. Bitcoinopoly (1471 points, 175 comments)
  20. BeijingBitcoins (1430 points, 100 comments)
  21. KoKansei (1330 points, 84 comments)
  22. MobTwo (1309 points, 93 comments)
  23. btcnewsupdates (1263 points, 153 comments)
  24. lubokkanev (1252 points, 298 comments)
  25. BitcoinXio (1251 points, 76 comments)
  26. taipalag (1248 points, 250 comments)
  27. mrtest001 (1075 points, 271 comments)
  28. LuxuriousThrowAway (1072 points, 163 comments)
  29. MarchewkaCzerwona (1046 points, 119 comments)
  30. cbeaks (985 points, 175 comments)
  31. SharkLaserrrrr (976 points, 135 comments)
  32. tippr (974 points, 523 comments)
  33. knight222 (963 points, 132 comments)
  34. PsyRev_ (941 points, 189 comments)
  35. radmege (919 points, 62 comments)
  36. Anenome5 (914 points, 182 comments)
  37. Churn (886 points, 75 comments)
  38. 324JL (855 points, 200 comments)
  39. emergent_reasons (854 points, 143 comments)
  40. TiagoTiagoT (841 points, 320 comments)
  41. bahkins313 (831 points, 121 comments)
  42. silverjustice (825 points, 62 comments)
  43. cryptorebel (812 points, 148 comments)
  44. scotty321 (811 points, 121 comments)
  45. DaSpawn (808 points, 113 comments)
  46. homopit (795 points, 100 comments)
  47. AcerbLogic (786 points, 205 comments)
  48. normal_rc (777 points, 59 comments)
  49. fiah84 (774 points, 136 comments)
  50. Deadbeat1000 (753 points, 61 comments)

Top Submissions

  1. No spend by ocist1121 (1189 points, 87 comments)
  2. 1 For whoever questions the utility of Bitcoin, here's banking summarized accurately by rlibec (783 points, 163 comments)
  3. Let's End the War and focus on the TRUE ENEMY by Anenome5 (719 points, 349 comments)
  4. Am I the only one that doesn't mind Bitcoin Cash being called "Bitcoin Cash" instead of just "Bitcoin" (for now)? by d3on (672 points, 401 comments)
  5. Warren Buffet's Berkshire is the single largest stockholder in BoA and WellsFargo. In case you were wondering about his attitude towards Bitcoin. by hunk_quark (614 points, 114 comments)
  6. MortuusBestia hits on a pitch-perfect way of looking at BCH's value proposition in epic comment on /BitcoinMarkets by ForkiusMaximus (604 points, 109 comments)
  7. coincall.io labels BCH a "shitcoin" by groovymash (586 points, 329 comments)
  8. Erik Voorhees: “Roger - please stop referencing me to back up your opinion that Bitcoin Cash is Bitcoin. It isn't. Bitcoin is the chain originating from the genesis block with the highest accumulated proof of work. The Bitcoin Cash fork failed to gain majority, thus it is not Bitcoin.” by sumsaph (585 points, 547 comments)
  9. Can’t believe this was available. My new license plate.. by VanquishAudio (581 points, 113 comments)
  10. Bitcoin Cash is upgrading on May 15 to 32MB max block limit by BitcoinXio (575 points, 335 comments)

Top Comments

  1. 322 points: rdar1999's comment in My dog ate my TREZOR. Check your recovery seeds folks!
  2. 314 points: my_next_account's comment in Erik Voorhees: “Roger - please stop referencing me to back up your opinion that Bitcoin Cash is Bitcoin. It isn't. Bitcoin is the chain originating from the genesis block with the highest accumulated proof of work. The Bitcoin Cash fork failed to gain majority, thus it is not Bitcoin.”
  3. 259 points: everyother's comment in 1 For whoever questions the utility of Bitcoin, here's banking summarized accurately
  4. 225 points: morli's comment in Can’t believe this was available. My new license plate..
  5. 209 points: groovymash's comment in coincall.io labels BCH a "shitcoin"
  6. 206 points: insanityzwolf's comment in Am I the only one that doesn't mind Bitcoin Cash being called "Bitcoin Cash" instead of just "Bitcoin" (for now)?
  7. 183 points: BitttBurger's comment in MoneyTrigz fails to raise more than $3,700 for Bitcoin.com lawsuit. Considers pulling the plug.
  8. 182 points: patrick99e99's comment in I used to think BCH was the bad guy, now I'm beginning to change the way I see it... Convince me that BCH is the real Bitcoin
  9. 175 points: RollieMe's comment in Trying to see both sides of the scaling debate
  10. 156 points: KillerDr3w's comment in My dog ate my TREZOR. Check your recovery seeds folks!
Generated with BBoe's Subreddit Stats
submitted by subreddit_stats to subreddit_stats [link] [comments]

Another week, another Mycelium feature description. This time one of our newest features: Message Signing!

Message Signing
First, make sure that Expert Mode is enabled in Advanced Settings.
Swipe to the left for a list of your addresses, select the address you wish to sign with, which will change the top bar to blue, click the dropdown menu, and select Sign Message.
Type in the message you wish to sign, and press the Sign Message button.
Your text will be signed, and you will get two options, Copy Signature to Clipboard and Share Text + Signature
The first option copies just the signature into your clipboard. You can use this if you just need to submit the signature by itself to a text challenge screen, such as to register on #bitcoin-otc channel.
The second option will share the text, address, and signature all bundled together in a format similar to PGP. For instance, in the example above, the shared result will look like this:
-----BEGIN BITCOIN SIGNED MESSAGE----- Hello world! -----BEGIN BITCOIN SIGNATURE----- Version: Bitcoin-qt (1.0) Address: 1Rassahgt3XSxKVJ62oSrQJxtH3wk4MKX
G50n39XFHXTYb4NRlzORTiKmsznIidz/s1gFZpXi8w/vEYapVLYbiTFloObeWHcslRedioAXVHB6Ckihs/p4Nns= -----END BITCOIN SIGNATURE-----
As for updates, we have released version 1.1.10 this past week, which added the following features:
  • message signing (go to Keys tab)
  • Hebrew, French, Korean, Polish translation
  • canonical S-values in signatures.
  • improved handing of exchange rates
  • remove Mtgox
  • added Kraken, Bitpay, Coinbase
  • new high-res launcher icons
Our developers (Jan and Andreas) are still working hard on Local Trader. We plan on getting the Testnet version out by Wednesday of this week, just in time for the Bitcoin Conference in Austin, TX. I'll be there, so feel free to grab me for a demo. The thing we're working on now is push notifications for the trader, which will alert you when you have a pending or accepted trade even while Mycelium is not running. I know some of you have asked for notifications for when you receive payments (because it's always great to hear the Ka-Ching! of incoming money ;D), and this will be the first step towards implementing that. Or rather will make adding that feature much easier.
submitted by Rassah to Bitcoin [link] [comments]

What is the best cryptocurrency wallet?

The procedure of token keeping is very similar to the keeping of fiat currency. The only difference is that you in that case you keep notes in a material wallet, and bitcoins – in a digital wallet, which contains keys. There are several types of cryptocurrency wallets:
Local
Mobile (Bitcoin wallet, Csap, Mycelium Blockchain)
Online (Csap, Circle, Blockchain.info, Strongcoin and Coinbase)
Hardware (Ledger, Best Wallet, KeepKey)
Paper wallets
We present a new global crypto market where any user can sell or buy different goods and services anywhere in the world using cryptocurrency. Alphateca is the platform that allows you to purchase many items and services using any crypto wallet that accepts Bitcoin, Bitcoin Cash, Dash, Ethereum, Litecoin.
Follow the link to get more details https://alphateca.com #alphateca #becryptoone #cryptowallet
https://preview.redd.it/aprmnfsn06211.png?width=256&format=png&auto=webp&s=3a5ee41372385534a175fbda1721b1159835c079
submitted by Alphateca to u/Alphateca [link] [comments]

an "open source" generic offline Linux QR/2key generator and secure cold storage wallet that is small portable quickly acquired and easy to use.

A Bitcoin Root for Linux/Android Phones
A simple Ledger Program and Offline Bitcoin Address/2Key Generator With a Friendly Integrated GUI Written in Linux and Installed on a Cold Bricked Android Phone.
Let me briefly introduce myself, . I am a 10 year Linux PC user (Fedora, Mint, ) which I installed myself through time on various old PCs , Laptops, and Netbooks either online or by usb. . I am trying to find someone who might be interested in writing a: Rooted, Data bricked, Linux Android Phone Program for me,
The program I am proposing and putting forth to the current Linux Open Source, community, for help on would be installed on a unwanted older android phones,
The exact program is “a Linux, “Open Source”, Offline Bitcoin Account Ledger & address QR code generator with a save to memory capability for backups These Backups can be done offline either through tetheusb to offline computer to usb thumbdrive, or to offline printer for paper backup, or without tether, to an already existing external SD card slot if available. And lastly it would have a friendly simple integrated ledger GUI.”
It's a vary small program root and total install, intended to be installed upon a rooted android device which is then immediately wiped clean of the pre existing software file system. The pure Linux open source program would then upon installation as a whole program be vacant and devoid of any files designed to recognize any data transfer capabilities of the physical phone hardware itself” After installation it becomes unaware of such things as bluetooth and wifi, hardware. Thus it cannot transfer data . . The phone is no longer a phone and it does not, nor ever will again' transmit data, for lack of a better term I am calling this cold bricking a phone, . The only means left of communication would be through the screen/camera of a single displayed QR code., This program is intended and permanent unless a re root and re installation is done. The Cold storage function has been "air gapped" The proposed program is so basic in its entire existence. It would easily not over exceed nor ever tax any current cell phone's memory resources or processing requirements. The more minimal and simplistic the entire program the better its meant to be a simple device. Free to the masses in need.
Some of the bottlenecks of the current growing Bitcoin system i can see existing in the world today are
!. It's current lack of a simple use for the common man. 2. It lacks of security for the first time user.
My reason for wanting to make this open source and free and easy is that it might help many people in emergency situations around the world today. Im hoping to make Bitcoin more immediately accessible to this population and the global community as well. This software upon root installation” should provide A safe and secure alternate currency offline cold wallet with quick reliable immediate access to all currently existing online crypto currency exchanges within the global network,. one can then use those existing exchanges to transfer with other entities such as ATM and personal one on one trade as well.and then one can safely secure ones funds and private keys offline. .
This cold bricking physically changes the devices hereafter purpose and function permanently. The old device is now a new device.”
An installed Bitcoin QR code offline generating software program should also have an easy to use user friendly GUI through a Account Books/Ledger GUI. . In the background it would run a Bitcoin Address/2Key offline creation program letting the user have the final 2key QR code image upon users command. It would use camera QR code transfer input and phone screen QR code transfer output The Account Book GUI will prompt the user for type of transfer and amount.
In the end you should have a secure offline cold wallet, portable, with internal offline QR code generating capabilities.
Why I personally want this program, . The Bitcoin phenomena itself has shown that a globally owned currency might be of good use in our world today. Especially in the areas of rescuing localized economic fiat collapse. For a large percentage of citizens living upon within these regional local communities (communities such as Venezuela and Greece 2017). It has in very recent modern times shown that BTC might be be a possible economic rescue tool. The gold and silver community have always believed that precious metals could be used in times of economic collapse, And a long history would dictate their reasoning to be a possible valid and working system. . But as of late there has been a new competitor in this arena of economic relief brought on by the advent of industrial computerization and the world wide web, . This digital global currency system currently BTC may in fact help all of humanity as a tool in stabilizing stressed individuals within collapsing economies. I believe both systems (precious metals and BTC) are valid opportunities and tools for economic rescue, And both can be tried. The Global Digital System is a new one yet to be looked into and fully tried.
In countries today such as those afore mentioned, We as of now currently can find a small percentage of the population experimenting with this global digital currency as refuge while their local fiat slowly collapses around them. This new global BTC currency system may be a large step forwards in protecting many local communities during economic duress in the near future. But it is not widely used amongst these troubled populations.
The problem I see in this new Global BTC System, is in its infancy and growing pains it still lacks ease of use, and availability, which then leads to mistakes in security of assets,
Today, as of this date, . in order to acquire and secure your digital currency in the event of an emergency, You must be tech wise concerning all the avenues of online and digital offline cold storage transfer. You must then purchase an airgapped cold wallet device and you must learn how to use and correctly manipulate this difficult technology, To do this You can download apps that are simply more middlemen in the system of exchange and some not cold secured. , Some apps are better than others, but most fail at differing points. If you do not use and learn how to tranfer amongst apps into total cold storage where you own your private key, Then you can learn make a linux bbotable usb, .and generate offline addresses. then From a laptop or PC, making paper copies on a printer or save offline on digital format, You must then also know the correct ways to transfer and connect this digital data without losing it. (sweeping/importing). For the common man this task is currently daunting and time consuming.
I believe this small open source program largely helps answer the “availability and ease” for most citizens in todays world whether in distressed economies or not, It would also stand to reason that the faster the individuals within an economicly distressed population can get onto a mass globally supported reserve currency, The sooner their people can begin to repair their local system. Once a local community fixes their economic problems the local people by nature while on BTC should then migrate back into the repaired local system. They should migrate naturally back once it becomes more desirable again at a local level, . as long as both systems (global and local) co exist and if the global currency is always freely open to the citizens across the world to invest in at will freely decentralized and anonymously, the global digital currency may have possible avenues of a stable reserve rescue for those in localized economic distress.
Yet, . . as I said it needs at this current time to be more quickly and readily available and easier for the people to use. This is whats lacking in the system as I see it, . . I dont think this new global digital currency is an answer to all and everything, . . . But I do believe it has its advantages. If you have a global wide increased acceptance and use of BTC on a grand geographically diversified scale
What I have done so far , . I have taken an old beloved and reliable android phone laying in my drawer, (a Samsung sch1200) and without rooting it, and by simply downloading two apps from the google play store , I have successfully made it a secure Bitcoin cold storage offline wallet that generates Bitcoin addresses and keys offline, it has a QR code scanner though the phone camera and a screen to display before said QR codes. The device I now have was inexpensive, widely available, and gets easier for me to use for BTC transactions every day, It also securely saves all my BTC offline where I am in charge of protecting those assets myself.
It is an offline bitcoin QR generator and cold storage device.
So if I have done this already why am I asking the Linux community for help.
The one I have right now is tedious as I have hodge podged it together with various apps and must manually create and move my QR data around between apps and ledgers. I Scan a QR code with “QR-Droid” save it manually, cut and paste both adresses and keys. Then save them on a word processor doc. All my addresses key pairs are then saved on individually named docs like unto a digital paper wallet and finally integrated into a single folder for cold storage backup,
As a side note for “random QR code adress and bitcoin key generation” I must, open a previously installed browser “Opera Mini” and the generate the random Bit address and QR key set from the previously saved offline page “bitaddress.org”, (I believe its a simple jave script HTML program, but im not sure),
I have successfully and easily then there after moved funds to my Coinbase and Mycelium accounts and back again, cross platform with no problems and great efficiency and ease, Its totally offline portable code generation and cold storage . IT works well for me, I am in control of my private keys, I also easily back up my data, and I do it often, . every time I generate a new key set I back it up to an external SD , . . and its extreamly portable.
A simple ledger checkbook offline QR cold storage system that creates and manages offline private keys in the background on a reliable no longer used dormant phone, since old phones might fail as in any technology, , (But mine is running strong), It has backup capabilities to either the existing usb tether or if so equipped and my favorite, . external SD card.
In closing I will say, . . .I have the utmost respect for the Linux open source community as a whole,. The only way I would ever pursue this endeavor would be through them, . any other way will not do.
And if by now it falls to nothingness like dreams never written , . . .At least I would urge you all to go to any nice high spot overlooking all people spread across your local community (city or town). Look out upon it, and then ask yourself, what would happen if these my friends below found out they had lost their local fiat currency suddenly all at once today.
And if you don't do that, . . Meh, . .I still have the utmost respect for you anyways, and its all good, . . yeah I just went Crazy today,
Anyways, Thank you for your time. .
P.S. and, . .A Friend I once met along the Bitcoin path recently saw what what I had so crudely made out of an old phone and made a video of it and put it online for me , , it can be found here
https://www.youtube.com/watch?v=0LTu59a5IJA&t=9s
And now I am tired of editing, . I quit, . .it is as it is, . . you'll just have to wade through it people, or get a couple of sentences in and toss it aside, . And .if you got this far, thank you for wading through it.
 Eclecticuniversalas 
02-21-2017
submitted by eclecticuniversalas to Bitcoin [link] [comments]

BIP for Proof of Payment | Kalle Rosenbaum | Jun 06 2015

Kalle Rosenbaum on Jun 06 2015:
Hi
Following earlier posts on Proof of Payment I'm now proposing the following
BIP (To read it formatted instead, go to
https://github.com/kallerosenbaum/poppoc/wiki/Proof-of-Payment-BIP).
Regards,
Kalle Rosenbaum
BIP:
Title: Proof of Payment
Author: Kalle Rosenbaum <kalle at rosenbaum.se>
Status: Draft
Type: Standards Track
Created:
== Abstract ==
This BIP describes how a wallet can prove to a server that it has the
ability to sign a certain transaction.
== Motivation ==
There are several scenarios in which it would be useful to prove that you
have paid for something. For example:
any device.
this period you can upload new content to the sign whenever you like using
PoP.
PoP.
is selected among the transactions to that address. You exchange the prize
for a PoP for the winning transaction.
With Proof of Payment, these use cases can be achieved without any personal
information (user name, password, e-mail address, etc) being involved.
== Rationale ==
Desirable properties:

A PoP should be generated on demand.

It should only be usable once to avoid issues due to theft.

It should be able to create a PoP for any payment, regardless of script

type (P2SH, P2PKH, etc.).

It should prove that you have enough credentials to unlock all the inputs

of the proven transaction.

It should be easy to implement by wallets and servers to ease adoption.

Current methods of proving a payment:
the request makes some sort of proof. However, it does not meet 1, 2 or 4
and it obviously only meets 3 if the payment is made through BIP0070. Also,
there's no standard way to request/provide the proof. If standardized it
would probably meet 5.
sign the transaction. This could meet 1 and 2 but probably not 3. This is
not standardized either. 4 Could be met if designed so.
If the script type is P2SH, any satisfying script should do, just like for
a payment. For M-of-N multisig scripts, that would mean that any set of M
keys should be sufficient, not neccesarily the same set of M keys that
signed the transaction. This is important because strictly demanding the
same set of M keys would undermine the purpose of a multisig address.
== Specification ==
=== Data structure ===
A proof of payment for a transaction T, here called PoP(T), is used to
prove that one has ownership of the credentials needed to unlock all the
inputs of T. It has the exact same structure as a bitcoin transaction with
the same inputs and outputs as T and in the same order as in T. There is
also one OP_RETURN output inserted at index 0, here called the pop output.
This output must have the following format:
OP_RETURN
{|
! Field !! Size [B] !! Description
|-
| || 2 || Version, little endian, currently 0x01 0x00
|-
| || 32 || The transaction to prove
|-
| || 6 || Random data
|}
The value of the pop output is set to the same value as the transaction fee
of T. Also, if the outputs of T contains an OP_RETURN output, that output
must not be included in the PoP because there can only be one OP_RETURN
output in a transaction. The value of that OP_RETURN output is instead
added to the value of the pop output.
An illustration of the PoP data structure and its original payment is shown
below.
T
+----------------------------------------------+
|inputs | outputs |
| Value | Value Script |
+----------------------------------------------+
|input0 1 | 0 pay to A |
|input1 3 | 2 OP_RETURN |
|input2 4 | 1 pay to B |
| | 4 pay to C |
+----------------------------------------------+
PoP(T)
+----------------------------------------------------------+
|inputs | outputs |
| Value | Value Script |
+----------------------------------------------------------+
|input0 1 | 3 OP_RETURN |
|input1 3 | 0 pay to A |
|input2 4 | 1 pay to B |
| | 4 pay to C |
+----------------------------------------------------------+
The PoP is signed using the same signing process that is used for bitcoin
transactions.
The purpose of the nonce is to make it harder to use a stolen PoP; Once the
PoP has reached the server, that PoP is useless since the server will
generate a new nonce for every PoP request.
Since a PoP is indistinguishable from a bitcoin transaction, there is a
risk that it, accidently or maliciously, enters the bitcoin p2p network. If
T is still unconfirmed, or if a reorg takes place, chances are that PoP(T)
ends up in a block, invalidating T. Therefore it is important that the
outputs of the PoP are the same as in T. The zero transaction fee in PoP(T)
is to minimize the incentives for miners to select PoP(T) for inclusion.
=== Process ===

A proof of payment request is sent from the server to the wallet. The PoP

request contains:

a random nonce

a destination where to send the PoP, for example a https URL

data hinting the wallet which transaction to create a proof for. For

example:

* txid, if known by the server

* PaymentRequest.PaymentDetails.merchant_data (in case of a BIP0070

payment)

* amount, label, message or other information from a BIP0021 URL

The wallet identifies a transaction T, if possible. Otherwise it asks the

user to select among the ones that match the hints in 1.iii.

The wallet creates an unsigned PoP (UPoP) for T, and asks the user to

sign it.

The user confirms

The UPoP(T) is signed by the wallet, creating PoP(T).

The PoP is sent to the destination in 1.ii.

The server receiving the PoP validates it and responds with “valid” or

“invalid”.

The wallet displays the response in some way to the user.

'''Remarks:'''
  • The method of transferring the PoP request at step 1 is not specified
here. Instead that is specified in separate specifications. See [btcpop
scheme BIP](btcpop scheme BIP).
  • The nonce must be randomly generated by the server for every new PoP
request.
=== Validating a PoP ===
The server needs to validate the PoP and reply with "valid" or "invalid".
That process is outlined below. If any step fails, the validation is
aborted and "invalid" is returned:

Check the format of the PoP. It must pass normal transaction checks,

except that the inputs may already be spent.

Check the PoP output at index 0. It must conform to the OP_RETURN output

format outlined above.

Check that the rest of the outputs exactly corresponds to the outputs of

T and that they appear in the same order as in T. An exception to this is
that any OP_RETURN outputs of T must not be included in the PoP. All output
value from the OP_RETURN must instead be included in the PoP output.

Check that the nonce is the same as the one you requested.

Check that the inputs of the PoP are exactly the same as in transaction

T, and in the same order.

Check the scripts of all the inputs, as would be done on a normal

transaction.

Check that the txid in the PoP output is the transaction you actually

want proof for. If you don’t know exactly what transaction you want proof
for, check that the transaction actually pays for the product/service you
deliver.

Return "valid".

== Security considerations ==
  • Someone can intercept the PoP-request and change the PoP destination so
that the user sends the PoP to the bad actor.
  • Someone can intercept the PoP-request and change for example the txid to
trick the user to sign a PoP for another transaction than the intended.
This can of course be avoided if the user is actually looking at the UPoP
before signing it. The bad actor could also set hints for a transaction,
existing or not, that the user didn’t make, resulting in a broken service.
  • Someone can steal a PoP and try to use the service hoping to get a
matching nonce. Probability per try: 1/(248). The server should have a
mechanism for detecting a brute force attack of this kind, or at least slow
down the process by delaying the PoP request by some 100 ms or so.
  • Even if a wallet has no funds it might still be valuable as a generator
for PoPs. This makes it important to keep the security of the wallet after
it has been emptied.
  • Transaction malleability may cause the server to have another transaction
id than the wallet for the payment. In that case the wallet will not be
able to prove the transaction for the server. Wallets should not rely on
the transaction id of the outgoing transaction. Instead it should listen
for the transaction on the network and put that in its list of transactions.
The first two issues are the same attack vector as for traditional, ie
BIP0021, bitcoin payments. They could be mitigated by using secure
connections.
== Reference implementation ==
[https://github.com/kallerosenbaum/poppoc poppoc on GitHub]
[https://github.com/kallerosenbaum/wallet Mycelium fork on GitHub]
== References ==
[https://github.com/bitcoin/bips/blob/mastebip-0021.mediawiki BIP0021]:
URI Scheme
[https://github.com/bitcoin/bips/blob/mastebip-0070.mediawiki BIP0070]:
Payment Protocol
[[btcpop scheme BIP]]
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BIP49 Derivation scheme changes | shiva sitamraju | Aug 30 2017

shiva sitamraju on Aug 30 2017:
Hi,
I wanted to discuss few changes in BIP49
*- Breaking backwards compatibility *
The BIP talks about breaking this, and but it really doesn't. I really
feel it should completely break this. Here is why
What would happen if you recover a wallet using seed words ?
  1. Since there is no difference in seed words between segwit/non segwit,
the wallet would discover both m/44' and m/49' accounts
  1. Note that we cannot ask the user to choose an account he wants to
operate on (Segwit/Non segwit). This is like asking him the HD derivation
path and a really bad UI
  1. The wallet now has to constantly monitor both m/44' and m/49' accounts
for transactions
Basically we are always stuck with keeping compatibility with older seed
words or always asking the user if the seed words came from segwit/non
segwit wallet !
Here is my suggestion :
  1. By default all new wallets will be created as segwit m/49' without
asking user anything. I think you would agree with me that in future we
want most wallet to be default segwit (unless user chooses a non segwit
from advanced options)!
  1. Segwit wallet seed words have a different format which is incompatible
with previous wallet seed words. This encodes the information that this
wallet is segwit in the seed words itself. We need to define a structure
for this
- XPUB Derivation
This is something not addressed in the BIP yet.
  1. Right now you can get an xpub balance/transaction history. With m/49'
there is no way to know whether an xpub is from m/44' or m/49'
  1. This breaks lots of things. Wallets like electrum/armory/mycelium
https://blog.trezor.io/using-mycelium-to-watch-your-trezor-accounts-a836dce0b954support
importing xpub as a watch only wallet. Also services like blockonomics/
blockchain.info use xpub for displaying balance/generating merchant
addresses
Looking forward to hearing your thoughts
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Bitcoin stolen - but how?

I just discovered that all the coin was swept out of three of my addresses and could use some advice on figuring out how it was done.
I recently got notice of the following transaction:
https://blockchain.info/tx/c4e131ef32c3db40803d70c5227cb9602887c97a9e33ccfbce59123e75f5e00d
In it, bitcoin was swept out of these addresses:
16oN2TiY7Eis5ZkCWkWr6Lhasb6iFBACiQ - a keypair generated in a Blockchain wallet, then imported into Mycelium for Android for use as a hot wallet.
1btc9HRDqhxYJcWHVdeCrMdzxg76u42at - another keypair generated at Blockchain but never imported to Mycelium
1worm8T6FFwbiNwCd4ncUq1kpugnjfcoY - an old vanity address from vanitygen imported to Blockchain
The common element between all 3 is that their private keys were stored w/ Blockchain. But I understood that they were hashed and stored encrypted locally in the browser. Is there a hack that can grab that data from the browser? I'm using Chrome for Windows and Mac to access Blockchain.
Also - any recommendations for software to scan for bitcoin-targeting virii on Windows 7?
EDIT - Thanks for the responses. I'm thinking I got lazy and left a Windows gaming machine go too long without a fresh install. I also used it for altcoin mining back in the day. Looks like I got keylogged. Time to change passwords and format some drives.
Having a Windows machine is like keeping a pet chimpanzee. They're fun to have around but eventually you're going to get your face ripped off.
submitted by mshadel to Bitcoin [link] [comments]

[noob] How do I save my bitcoins?

I don't know if I even asked the question right. So let me explain.
I opened a bitcoin wallet using Mycelium app on android. I have a few satoshis in it at the moment. I know that's nothing. I have made a backup at one point and created a master seed (I have no idea about any of that, I just followed the instructions).
Should I keep my bitcoin address private? can anyone steal my bitcoins if they found out my address?
Also I've heard people saying to keep the backup safe or you'll lose all the coins. does that mean my bitcoins are stored in my phone's storage right now and if I format the phone I'll lose all of it for good? If so how do I make a copy of that backup somewhere else?
I'm sorry for the stupid questions. But I really want to understand. Thank you.
submitted by BambaZillah to Bitcoin [link] [comments]

Mycelium + desktop wallet

Hi everyone!
I opened an account on Kraken since a lot of people here on Reddit recommended it for Europeans, and now I'm setting up my personal wallet, following Reddit advices not to leave your money on an online exchange system, even though in my case we are talking about small amounts (<€100).
I installed Mycelium on my mobile 'cause that was the most recommended client. Now, I'd like to also install a client on my desktop since I could use it to buy online. And this is where I get lost. Is this safe? Or I risk the accounts to go "out of syncs" and lose money? I was thinking of using Electrum. I can't understand if all I need to do then is to share the .dat files or if some issues could arise.
I read a few articles but they didn't help me out (some stuff is a bit too technical for a total newbie), these for example: http://bitzuma.com/posts/five-ways-to-lose-money-with-bitcoin-change-addresses/ http://bitcoin.stackexchange.com/questions/13687/which-bitcoin-wallets-let-you-export-to-a-universal-wallet-format/13823#13823
I guess that a web wallet will help here but I don't want an online service.
Should I just use two wallets and split the money between them, or move it back and forth?
Also, I made a backup of the Mycelium wallet, even though there's no money yet, should I verify it now, and how?
Thanks a lot for the help :-)
submitted by FrothOnTheDaydream to BitcoinBeginners [link] [comments]

Importing old encrypted private keys????

This has me stymied.
tl;dr: I have base64-encoded encrypted private keys that I can't figure out how to decrypt to use.
So, I finally remembered what way back I threw some BTC at cex.io, and I wanted to put them back into a wallet I had control over. Well, their system is shit, and apparently though I had once verified a phone for 2fa with them, they only take the authenticator code, and my authenticator code isn't working.
So, they need a signed hash for the deposit address. Well, back then I was using Bitcoin Core instead of Mycelium, but no problem! (Hah! It was the bitcoin android app) I have encrypted exported private keys, so it's just a matter of importing them and then signing, right? Wrong. So wrong.
So my keys look something like
U2FsdGVkX1+GZiYTSE/0sBQqiTesL3pTdh2UmTm/OjFl+lFrj0qy...
now, importprivkey doesn't work in core. Well, are these really encrypted? Running a base64-decode on them returns Salted__†f&HOô°*‰7¬/zSv ”™9¿:1eú... so yeah, that looks like a properly encoded encryption string.
Now, the internet gives me plenty of references on how to import an decrypted private key, or application-specific types of encoded keys, but this looks pretty straightforward yet nothing recognizes the format.
I mean, I could even write something up in a pinch as long as I knew the exact algos these types of exports were put through, but it seems insane there isn't a tool.
Trying this stackexchange comment just gives me bad decryption results (which could be anything from the suggested algo to expected formats, or even possibly that the decryption key has an !). Screenshot
Help?
Solution: Use a decryption of the form
openssl enc -in FILE_OF_KEYS -a -d -salt -aes256 -pass pass:"PASSWORD_HERE"
submitted by tigerhawkvok to Bitcoin [link] [comments]

What is wrong with my current cold storage method?

Today we are going to discuss cold storage and some specific problems with cold storage. While this applies directly to the Secret Key portion of a key-pair; it also applies to the seed used to back up HD wallets and hardware wallets.
The best way to keep you seed/secret key safe is to have multiple copies in multiple locations perhaps with multiple formats and even better if the keys are split. However not everyone has access to multiple locations, or access to land long term, or more than one place to store their things. This is an examination of faults with individual methods; and not a comprehensive plan, obviously.
Not to say everything is all bad but there are many potential weakness out there, and some in the Bitcoin and crypto community like to know the edge cases of things.
I will also highlight some of the aspects of the Keyois Capsule which is a 'physical bitcoin'.
A physical Bitcoin is a cryptographic key pair, a physical key printed and affixed to what has always been before a coin. The first physical bitcoin coin was the Casascius coin, since then the world of physical bitcoin coins has blossomed as a fun part of the Bitcoin world.
We will focus on mediums relating to cold storage and not ones designed for more everyday use, but this applies to the seed you save to keep your everyday spending wallets safe and backed up.
We will assume you generated your keys securely and that you already have them on some medium. We will also have to ignore endpoint physical security because they can all be carried away the same. Remember your cell phone /hardware wallet/ computer client are only as good as where you put the backup seed phrase, which can be thought of as data much like the SK discussed below.
Written on a piece of paper
Printed on a piece of paper
On laminated paper
Engraved / etched/ ablated/ stamped on a piece of metal
Stored digitally on a computer
Stored digitally on CD, floppy disk, laserdisc, or mini-disc
Stored digitally on a flash drive
Backups are essential for digital data Computer code for performing operations can be corrupted in transfer or in operation. Special systems exist and procedures help data to last longer. For ideas, see this archive.gov page Remember to store in multiple locations. You can lose everything in single structure
A physical bitcoin coin
**What can solve most of these problems? A combination of good backup procedures and encryption. **
If you have permeant access to more than one location (people who live in big cities, without family or cars have a hard time with this) or have people you trust with your money (don't) then look into using some form of Multi-signature option.
The Keyois Capsule is a crypto piggy bank; it can be funded from the outside but you to break it open to get them out. You give me a BIP38 encrypted key pair (well the address not the public key) and I engrave it in this tamper evident and time resistant package. You still have to hold on to the pass phrase that allows you to decrypt it; that is however the same problem as all methods with BIP38 encryption. How to store this without having to trust anyone but still being assured of it's security?
  • Engraving, embossing, or stamping on a sheet of metal is one option; however the metals that are easiest to stamp are ones that melt in a house fire. They could be put in a glass jar that's filled with aerogel and buried. These is the best readily available option for most people but it really can be tedious. - This puts you back at anyone who can see it can steal it so dip in plastic dip, wrap in duct tape, bake in clay, encase in concrete, whatever just don't leave unencrypted keys visible!
  • The cryptosteel is another ready-made option
  • Have the words etched onto glass at home with off the shelf products; but be carful of this idea because the glass can shatter from impact and heat or even sudden temperature changes
  • Anodize the words yourself on a pieces of metal, there used to be a service to help use your home printer to print the words with some chemicals you can buy
  • Bake them in clay, then encase that in epoxy resin so it can't shatter. then paint the outside, in the future you can solvent the paint off and see the written seed
  • Use a combination of techniques to split the seed so that it is safe(because split and separated) and redundant (because backed up).
The most cost effective way for a 'normal' person (without their own land, without more than one location, and who cannot trust anyone else with their funds) to keep their backup seed/ secret key safe from damage from the elements would probably to buy a stamping kit and hammer and some stainless steel sheet or bar, Aluminium can be okay if you have the right alloy but better safe than sorry.
submitted by ProfBitcoin to Keyois [link] [comments]

Funding a Greenaddress Wallet

Hi, I just received my HW.1 hardware wallet and have set up a Greenaddress wallet. I am just wondering (as a noob), how do I fund this address because the address format is not the same as a Bitcoin address?
In the Green Address Chrome extension I click 'Receive Money', and then the QR code but when I scan it with the Android Mycelium wallet to add the address to the address book it says unrecognized format.
Thanks so much in advance!
submitted by reallybigpotato to greenaddress [link] [comments]

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With the Mycelium Bitcoin Wallet you can send and receive Bitcoins using your mobile phone. HD enabled - manage multiple accounts and never reuse addresses ( Bip32 / Bip44 compatible) Masterseed based - make one backup and be safe for ever. Bitcoin : I tested KeepKey + Mycelium + SegWit so you don't have to. **TLDR:** you can send and receive Bitcoin to and from native SegWit (Bech32) addresses using KeepKey + Mycelium, but not using KeepKey Also tried the sweep feature but it isn't recognizing the format of the keys. – hortstu Oct 21 '17 at 4:25. What if you have mycelium single bitcoin address. Its got a different back up and they dont give you the private key. – abeikverdi Dec 13 '17 at 17:18. add a comment 0. mycelium by default uses the seed to generate private keys. you must have this seed of 12 words (available when ... A bitcoin wallet represents a software program program which shops bitcoin (BTC) $7183.47 -1.12% private keys. Typically, wallets come in hardware and software program for, the former being often called a hardware wallet. Basically, they succeed to you access to your public Bitcoin address, often with Bitcoin Core and an internet connection, thus facilitating the buying and selling of ... Bitcoin puts the current compact-format target and the arbitrary-precision "extraNonce" number there, which increments every time the Nonce field in the block header overflows. Outputs can be anything, but Bitcoin creates one exactly like an IP address transaction. The extranonce contributes to enlarge the domain for the proof of work function. Miners can easily modify nonce (4byte), timestamp ...

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How to create a bitcoin wallet and get a bitcoin address on your android phone

In this video I go through the process of loading funds from a bitcoin paper wallet onto an Android phone using the Mycelium Bitcoin Wallet app. I also show how to create paper wallets using the ... 1) Send a DM to @jfgi on Twitter with your public BTC Address 2) Receive a DM from @jfGi with your free account url linking #bitcoin to your #twitter name: https://jfgi.cc/rafiq is mine 3) Add ... Create a bitcoin wallet and get a bitcoin address on your android phone. You can also transfer your bitcoin to your bank account, recharge your mobile, send bitcoin to a friend from zebpay. app ... How to change your "Email Address (Primary Email) ... How to Setup Mycelium Bitcoin Android Wallet To Store Bitcoins - Duration: 18:15. CoinSutra - Simplifying Bitcoin & Cryptocurrency Recommended ... This video is for Bitcoin gold wallet address.

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