Questions tagged [encryption]

Encryption is the process of encoding information into a ciphertext that only authorized parties can decode. Encryption isn't used in the Bitcoin protocol itself, however it can be used e.g. for encrypting wallet backups or peer-to-peer communications.

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How long would it take a large computer to crack a private key?

I am doing a presentation on Bitcoins and I was looking for some calculations to make people feel safe about the private key encryption. Please first answer, how long in bytes the private key is, ...
shoeless joe's user avatar
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44 votes
10 answers
12k views

How can I keep my wallet secure?

The standard Bitcoin client does not encrypt wallet files, so any malicious user that gains access to this file will be able to transfer all the coins to their own wallet. Furthermore, if I lose the ...
Michael McGowan's user avatar
19 votes
3 answers
20k views

Are there Bitcoin password crackers I can use to recover forgotten passwords?

I've lost the password to one of my wallets (it's a small one, don't worry). I was sure I remembered the password ... but evidently I don't. Is there a program that I can use to brute-force my ...
ripper234's user avatar
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17 votes
4 answers
37k views

Won't ASIC miners eventually break SHA-256 encryption?

I might be confused as to how Bitcoin works, but as far as I can tell, ASIC miners are getting better every year and faster at cracking SHA-256 encryption. Won't this cause the eventual complete ...
Paul Omans's user avatar
15 votes
1 answer
8k views

How does bitcoind generate a new address if the wallet is encrypted

Suppose that my wallet is encrypted with a passphase and currently I have not provided bitcoind with the passphrase to access the private keys section of the wallet. If I enter: bitcoind ...
Sam's user avatar
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14 votes
3 answers
4k views

How would one "Encrypt" a message using a Bitcoin *public key* and use its private key to decrypt it?

I have the following text string: This is a test message. Using my bitcoin public key (bitcoin address?), how can I encrypt this message? How would I decrypt the message using a bitcoin private key?
Patoshi パトシ's user avatar
12 votes
2 answers
326 views

Can I force my wallet to only have news keys, post-encryption?

Now that v0.4 of the bitcoin client has encryption I've gone ahead and encrypted the keys in my wallet. But I had previously made backups of my (unencrypted) wallet and those keys are the same keys ...
Stephen Gornick's user avatar
11 votes
1 answer
3k views

How to Call JSON-RPC SendToAddress when the Wallet is Encrypted?

I'm using JSON-RPC to send commands to my bitcoind, and it works fine. Now I want to encrypt my wallet. When I've done that, I will need to send the passphrase when calling SendToAddress. How do I do ...
bitboy9999's user avatar
10 votes
1 answer
4k views

How does the Electrum wallet encryption work?

Nube bitcoin question... I created an electrum wallet, and can find it under appdata on my windows machine. When creating it I set up a pass phrase and password. I sent a small transaction into one ...
steve's user avatar
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9 votes
2 answers
6k views

If I lost my public keys, could I recover them from the private key? [duplicate]

Possible Duplicate: How are public & private keys in an address created? If I lost my public key, but still have the private key, is it possible to recreate the public keys. How many public ...
shoeless joe's user avatar
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9 votes
1 answer
1k views

Does the BerkeleyDB-based wallet.dat implementation leak private key data?

I read this little nugget on the bitcoin client bug tracker: the bdb binary log files can also contain sensitive data such as private keys Is that true? Does this mean that even with an encrypted ...
Thilo's user avatar
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8 votes
2 answers
8k views

Backing up my bitcoin wallet - is wallet.dat all I care about?

I know that there are many duplicates of this but I'm hoping that the way in which I word this explains and helps not just me, but others as well. In any of the coin wallet bitcoin and the alt coins,...
Tom Stickel's user avatar
8 votes
5 answers
3k views

BIP38 or Brain wallet?

I have seen many videos about paper wallets and different ways to store BTC. And I have choose to store using a cold wallet (paper wallet). But I am not sure what option I should choose: a normal ...
Tor's user avatar
  • 81
7 votes
3 answers
2k views

Using the bitcoin wallet PKI for message encryption

Is it possible for a message sender to encrypt a message string with a receiver's public wallet address, email this ciphertext to the receiver and then have the receiver decrypt the message using ...
NullPointer's user avatar
7 votes
2 answers
2k views

Is this how I should calculate a Double SHA256

So I have a function called sha256 which will take a string and return the SHA-256 hash. var First = sha256('myfirstSHA'); And the output is the hex: ...
Will-In-China's user avatar
7 votes
1 answer
5k views

How to import a private key to an encrypted wallet (on standard client)

I have a standard client (QT client on OSX) with an encrypted wallet. I've tried to import keys with pywallet, but while it claimed to be importing them, when I ran again the bitcoin client, it said ...
o0'.'s user avatar
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7 votes
1 answer
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Forgot wallet encryption password, are any brute force tools available? [duplicate]

I have an idea of what my password should be, but am missing something. Are there any tools or bash scripts to brute force my wallet passwords? If a dictionary is required, I can pre seed it as ...
makerofthings7's user avatar
7 votes
1 answer
1k views

How to 'attach' metadata to a bitcoin receive address

I need to generate a receive address that is directly associated with some metadata, M, that forms part of a verifiable contract. I require that customers can verify that an address really was ...
grebit's user avatar
  • 71
7 votes
1 answer
569 views

What OpenCL video cards (or FPGAs) are best for multiplication?

I'm benchmarking some Bitcoin related software and am looking for cards that are better at parallel multiplication vs parallel addition. Is there any prior work that may have this information? ...
makerofthings7's user avatar
6 votes
3 answers
1k views

Papers/Books on how bitcoin works from a mathematical perspective?

I'm a math student interested in Cryptography. Is there any paper or book which explains, in mathematics and cryptography terms, how bitcoin (more general, a digital cryptocurrency system) works? In ...
user avatar
6 votes
1 answer
466 views

What happens when an encrypted wallet runs out of keys?

Say someone wanted to be evil to the main client and set its wallet to contain one key, lock it, and then start mining. After the first block was generated, the client would traditionally create a new ...
ThePiachu's user avatar
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6 votes
2 answers
502 views

Do keypool keys from an unencrypted wallet backup become unusable once I encrypt my wallet?

I'm a little confused by this, which i found in the technical documention: When wallet passphrase enrcyption becomes enabled, any unused keys from the keypool are flushed (marked as used) and new ...
noobStuff's user avatar
6 votes
3 answers
21k views

How do I unlock, decrypt, Bitcoin wallet?

I'm new to Bitcoins and I downloaded the new beta version with the encrypted wallet. I encrypted my wallet but I have no idea on how to decrypt it. It is locked. How can I unlock/decrypt my wallet? ...
bobanderson's user avatar
5 votes
1 answer
3k views

How can a deterministic wallet have one private key but multiple public keys

If we take for example bread wallet. There is one mnemonic to remember, which means one private key? But when you use the app, your public address constantly changes. So more than one public key? ...
Kyle Graham's user avatar
5 votes
3 answers
4k views

How do Ledger Backups get stored?

Scenario Say you have configured a ledger wallet with 10 BTC and 10 ETH. You then lose this said wallet but you have the 24 unique words. You buy another ledger wallet enter the 24 words and BAM, ...
Rstack's user avatar
  • 53
5 votes
2 answers
6k views

Is this the proper way to use Bouncy Castle to generate a Bitcoin compatible key?

I'd like to use Bouncy Castle to generate the keypair for use with all *coin variants. Is this the correct implementation to get the correct ECC curve that the *coin variants use? Org....
makerofthings7's user avatar
5 votes
1 answer
457 views

Does a Vanity Address reduce the randomness / entropy of the private key? Is there cryptographic proof?

Since a vanity address discards many "valid" keys in order to find one that matches a pre-determined string, I think that the "randomness" of the data would be reduced, thus weakening the key. Is ...
makerofthings7's user avatar
5 votes
6 answers
2k views

Safely convert paper wallet to encrypted online wallet

I started investing a not insignificant part of my salary into BTC a few years ago. I created 10 paper wallets (using bitcoinpaperwallet.com) on a dedicated laptop disconnected from the Internet. I ...
user18343's user avatar
4 votes
1 answer
446 views

A security need for Bitcoin to fork to quantum resistant algorithm in a few years?

in just a few years I believe that quantums will exist that break asymmetric ciphers, and bitcoin is based on asymmetric ones like public-key-cryptography, correct? Symmetric algorithms are supposed ...
johnsmiththelird's user avatar
4 votes
3 answers
2k views

Comparing Bip 38 to AES256

Can anyone explain what are the advantages of using BIP 38 Bitcoin wallet encryption to simply encrypting the private key with AES256?
Assaf Shomer's user avatar
4 votes
1 answer
243 views

BIP324 encrypted packet structure

I recently saw the BIP 324 proposal. It shows us there can be some privacy enhancement by using ECDH secrets and encryption algorithms such as ChaCha20 and AEAD-ChaCha20-Poly1305. The proposal ...
Loopite's user avatar
  • 301
4 votes
2 answers
1k views

Should I put my bitcoin wallet on an encrypted disk or not?

Is it really beneficial to put my bitcoin wallet on an encrypted disk (LUKS encrypted)?
user123455's user avatar
4 votes
2 answers
8k views

Private key to WIF process

I have a private key for a storage bitcoin wallet (there's not much in there I'm just testing methods) but it is in private key form and to import it to my main wallet I need to convert it into WIF. ...
Piestar's user avatar
  • 41
4 votes
4 answers
483 views

How can I test and verify a vanity key before I send coins to it?

I ran vanitygen and oclvanitygen on the same machine, and realized after my run that both exe's share the same output file. I've had experience in the past where many programs append to the same TXT ...
makerofthings7's user avatar
4 votes
1 answer
151 views

Is two-phase encryption planned for the standard client?

Currently, the standard client supports encryption, but only for actions that change its state (send money, generate address). I would like the client to require two passwords - one to view any ...
ripper234's user avatar
  • 26.6k
4 votes
1 answer
179 views

Has Bitcoin Cores encryption wallet security ever been bypassable?

Every few years there seems to be an exploit found in Trezor that allows people to bypass the security. I was wondering has there every been the same case for Bitcoin Core wallet encryption?
Toodarday's user avatar
  • 227
3 votes
1 answer
234 views

Is BIP324 v2transport redundant on Tor and I2P connections?

Just testing the recent BIP324 on my node, since Bitcoin Core v26 and having v2transport=1 in bitcoin.conf set, I have noticed that I am receiving some incoming connections using the v2 transport ...
2F4kT0r's user avatar
  • 71
3 votes
2 answers
2k views

Multibit security with regards to "backup" folders

I'm using the MultiBit client to manage my wallet (right here on my computer), but I am concerned about the security with regards to the *-backup folders that it creates automatically. When I inspect ...
pancake's user avatar
  • 133
3 votes
1 answer
2k views

Bitcoin-Qt - backing up unencrypted wallet then encrypting it

If I back up unencrypted wallet.dat somewhere safe (TrueCrypt volume) and then encrypt the wallet by Settings / Encrypt Wallet, will my backup still be useful? I think the message after encrypting the ...
davidhq's user avatar
  • 133
3 votes
2 answers
898 views

Does the public key associated with an address become part of the public record after it has been used to spend?

Since bitcoin addresses are hashes of public keys and not public keys as such, if one wanted to craft a message that could be decrypted by the generator of an address, that can't be done just with an ...
david nicol's user avatar
3 votes
1 answer
7k views

How can I fix corrupted encrypted wallet.dat?

My only one backup of encrypted wallet is corrupted (last time when backed it up i probably didn't shutdown bitcoin-qt), with hex editor i found in it: mkey ckey (117 that looks fine) Does this ...
nyaa's user avatar
  • 171
3 votes
2 answers
1k views

What is the current state of BIP 38 (encrypted paper wallet) integration with cell phone wallets?

Given current implementations, is there a wallet that I can use to scan a private key, then enter in the password as a PIN, and the wallet will send from the key and sweep the rest onto a key ...
amashi's user avatar
  • 33
3 votes
3 answers
5k views

Wallet is encrypted and currently locked, How can get unencrypted (unlocked) it?

Wallet is encrypted and currently locked, How can I unencrypted the wallet to unlock? Because of my Bitcoin wallet not getting synchronising currently, so I could not get bitcoin balance on one of my ...
Jagdish Ram's user avatar
3 votes
1 answer
691 views

How complex can my bitcoin wallet encryption key be?

What are the requirements and limitations of the password that the satoshi bitcoin wallet allows the user to set?
osmosis's user avatar
  • 5,529
3 votes
1 answer
177 views

Why does the chacha20 implemented in the Bitcoin Core use a 64 bit nonce?

The draft of chacha20 uses a 64-bit nonce, but the final version of chacha20 specification uses a 96-bit nonce. The #9792 PR adds chacha20 to Bitcoin Core. We can see the function ChaCha20::SetIV(...
siv2r's user avatar
  • 33
3 votes
2 answers
5k views

Is this how to generate a bitcoin address with python?

So I have already the public key. My question is if I'm applying correctly the b58 encoding, since bitcoin uses b58check, and also adds x00 prefix. Can somebody explain me that? Thanks. import ...
John Smith's user avatar
3 votes
2 answers
2k views

Do all Cryptocurrencies uses same Public key Cryptography algorithm?

I have been trying to read about how Public key cryptography works and I have just understand what public key cryptography is and how it differs from symmetric key cryptography. I have also just read ...
Bitcoin123's user avatar
3 votes
1 answer
2k views

How should I encrypt a bip39 mnemonic with a password?

With no server and only in the browser I'm generating an a bip39 key and giving the user the mnemonic to store some place safe for restoring, I also want the user to be able to login with a password. ...
Will-In-China's user avatar
3 votes
1 answer
2k views

Do i delete the Bitcoin folder & data directory in Appdata after i copy it on an encrypted drive?

I am trying to complete the instructions described here https://en.bitcoin.it/wiki/Securing_your_wallet#Windows . I have already done the Truecrypt part and installed the Bitcoin client. But i have ...
NewBitcoiner's user avatar
3 votes
1 answer
183 views

Why bitcoind will shutdown after encryptwallet?

As mentioned in the bitcoin-cli document for encryptwallet command, bitcoin daemon will shut down after encrypting a new or unencrypted wallet. My question is about the reason for shutting the node ...
Vahid Kharazi's user avatar