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Questions tagged [encryption]

For questions relating to encryption operations and algorithms as they apply to crypto-currencies specifically.

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2
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2answers
2k views

How does the Bitcoin Standard Client wallet encryption work?

I encrypted my wallet using Bitcoin QT, then closed the application. When I restarted Bitcoin QT, it did not ask for the passphrase. But I could still access the wallet. How is it possible to access ...
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1answer
905 views

What encryption does Electrum use for private keys in wallets?

Electrum can encrypt the private keys in wallets with a user entered password. But what encryption algorithm is used? I'd hope it is reasonably strong crypto. I've looked at the Electrum docs and can'...
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1answer
693 views

How do the blue encrypted bitcoin paper wallets work?

Via https://www.bitaddress.org I saw you can get a paper wall but with encryption and a passphrase. What are the steps of using the wallet with the passphrase? It seems the address is on the left ...
7
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3answers
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 ...
1
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1answer
413 views

In the sourcecode, what does this line mean that recovers the key from the signature?

I understand that the public key (Q) can be extracted from a signature (r,s), but I'm having trouble understanding this line: if (!key.Recover(hash, &vchSig[1], (vchSig[0] - 27) & ~4)) The ...
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1answer
1k views

Locking litecoin wallet with JSON-RPC

There is this very helpful post detailing how to lock and unlock your bitcoin wallet using walletlock and walletpassphrase api calls. Unfortunately the litecoin api does not boast these features. I ...
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1answer
1k views

Storing an encrypted private key on a server

I am planning on building a small e-wallet website to learn the basics of encryption and handling accounts, transactions, and balances in Bitcoin. I want to learn how to make a website where the ...
2
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2answers
1k views

Is there anyway I can recover my passphrase? [duplicate]

I have a wallet for the bitcoin qt wallet but I accidentally deleted the only copy of my encryption passphrase... I have read about something called brute force but I'm not entirely sure on how its ...
7
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1answer
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 ...
3
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1answer
2k views

What are the drawbacks (if any) of encrypting your wallet with Bitcoin-Qt?

Basically, is there any reason not to encrypt your wallet? The only drawback I can think of is forgetting your passphrase and losing access to all your bitcoins.
2
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1answer
177 views

Is the keypool erased when changing wallet password?

In Bitcoin-qt, when a previously unencrypted wallet is encrypted, the keypool is erased and replaced with new keys. Does this also happen when the password of an already encrypted wallet is changed?
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0answers
343 views

How can I access my private keys? Will the key get lock further if I enter the incorrect password too many times?

I exported my private keys and Multibit unencrypted but when I try to import the key files I am being asked for a password... copying the the key from text edit and pasting it into blockchain results ...
3
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3answers
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 ...
2
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3answers
823 views

I never encrypted my wallet.

When I installed it I never encrypted it. I then funded the address and I now have 1.1 bitcoins. But when I tried to send or create a new address it asked for a passphrase. I tried every possible ...
3
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1answer
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 ...
6
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2answers
416 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 ...
10
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1answer
3k 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 ...
5
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1answer
334 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 ...
5
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2answers
4k 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....
3
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2answers
935 views

How does an encrypted wallet persist used keys from “getnewaddress” and the keypool after a restart?

I'm reading this wiki on wallet encryption and am confused on how I can call getnewaddress as described here and where that is being tracked after a restart of bitcoind. When a wallet is encrypted,...
2
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2answers
242 views

Does FIPS 140-2 crypto certification matter for Bitcoin?

I'm implementing part of the Bitcoin client in C# and noticed that I have the choice between FIPS 140-2 and non certified versions of SHA256. Supposedly both versions give the same hash. Does the ...
7
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1answer
553 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? ...
4
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4answers
376 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 ...
7
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1answer
10k views

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 ...
3
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2answers
862 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 ...
6
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1answer
1k views

Where and how is secp256k1 used within Bitcoin?

Bitcoin is unique that is uses secp256k1 to secure it's transactions; and any cryptographic attack against this algorithm is probably going to be percieved as an attack against the bitcoin network. ...
2
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0answers
247 views

Is there a way to import a private key already protected with the passphrase?

Let's say I have a hot wallet that has passphrase encryption enabled. Then let's say a large withdrawal needs to occur but the hot wallet has insufficient funds and a transfer from cold storage is ...
15
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1answer
7k 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 ...
3
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1answer
664 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?
7
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1answer
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 ...
15
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3answers
10k 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 ...
39
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7answers
51k views

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, ...
6
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1answer
428 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 ...
4
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1answer
143 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 ...
1
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3answers
377 views

Where can I go to read up on encryption methods used in Bitcoin?

Where can I go to read up on encryption methods used in Bitcoin? I am particularly interested in the idea that I can use a private key to sign something and it proves to the world I have the private ...
6
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3answers
15k 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? ...
3
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1answer
478 views

Does Bitcoin wallet encryption also protect my sending and receiving addresses?

Bitcoin wallet encryption makes sure (by encrypting the private keys with a passphrase) that someone who finds your computer or your Dropbox or your backup drive (including wallet.dat) cannot spend ...
9
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1answer
770 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 ...
3
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1answer
543 views

How do we have one-to-one mapping given the key size differences?

If public keys are 34 characters long, and private keys are 61 characters long, then the combinations of 34 characters is not sufficient to give each combination of 61 characters a unique pair. My ...
17
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2answers
12k views

Why does the length of a bitcoin key vary?

Why does the length of a bitcoin key vary? Why aren't they all the same length?
9
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2answers
4k 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 ...
11
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1answer
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 ...
12
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2answers
300 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 ...
43
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9answers
9k 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 ...