Bitcoin Forum

Bitcoin => Bitcoin Technical Support => Topic started by: grace_monkey on April 20, 2015, 12:52:23 PM



Title: Recover the password for the bitcoin wallet by using an unencrypted backup
Post by: grace_monkey on April 20, 2015, 12:52:23 PM
I’ve lost my password for bitcoin wallet :)

But I have unencrypted backup of the wallet that was made a year ago.
Unfortunately, bitcoins stored on addresses that contained only in ciphered wallet, not in unencrypted backup.
But some addresses are contained both in the encrypted and unencrypted wallet backup

I have idea:
- choose any address that contained in both the ciphered wallet and unencrypted backup
- extract private key for address from unencrypted backup
- extract ciphered private key from ciphered wallet
- compare two extracted strings and get password for the wallet

I have superficial knowledge of cryptography, but this should work :)

my idea is feasible?
Anyone know about software that can do what I described?
Can anyone create such software for reward?


Title: Re: Recover the password for the bitcoin wallet by using an unencrypted backup
Post by: InceptionCoin on April 20, 2015, 01:39:51 PM
Try to load you backup wallet first. Bitcoin-qt save up to 100 addressess for future using in the wallet to use in the future, so if you made less then 100 operations you are probably have all used privkeys in the old wallet.
As i know bitcoin-qt encrypt whole wallet not each address independently, so your plan probably not feasible.


Title: Re: Recover the password for the bitcoin wallet by using an unencrypted backup
Post by: scientific on April 20, 2015, 01:46:48 PM
I’ve lost my password for bitcoin wallet :)

But I have unencrypted backup of the wallet that was made a year ago.
Unfortunately, bitcoins stored on addresses that contained only in ciphered wallet, not in unencrypted backup.
But some addresses are contained both in the encrypted and unencrypted wallet backup

I have idea:
- choose any address that contained in both the ciphered wallet and unencrypted backup
- extract private key for address from unencrypted backup
- extract ciphered private key from ciphered wallet
- compare two extracted strings and get password for the wallet

I have superficial knowledge of cryptography, but this should work :)

my idea is feasible?
Anyone know about software that can do what I described?
Can anyone create such software for reward?

You can't do this anyway. Bitcoin Core uses AES. Read here: https://en.wikipedia.org/wiki/Known-plaintext_attack


Title: Re: Recover the password for the bitcoin wallet by using an unencrypted backup
Post by: grace_monkey on April 20, 2015, 03:24:37 PM
Try to load you backup wallet first. Bitcoin-qt save up to 100 addressess for future using in the wallet to use in the future, so if you made less then 100 operations you are probably have all used privkeys in the old wallet.
As i know bitcoin-qt encrypt whole wallet not each address independently, so your plan probably not feasible.

if you encrypt your wallet - bitcoin deletes all unused addresses and refills key pool


Title: Re: Recover the password for the bitcoin wallet by using an unencrypted backup
Post by: grace_monkey on April 20, 2015, 03:57:09 PM
I’ve lost my password for bitcoin wallet :)

But I have unencrypted backup of the wallet that was made a year ago.
Unfortunately, bitcoins stored on addresses that contained only in ciphered wallet, not in unencrypted backup.
But some addresses are contained both in the encrypted and unencrypted wallet backup

I have idea:
- choose any address that contained in both the ciphered wallet and unencrypted backup
- extract private key for address from unencrypted backup
- extract ciphered private key from ciphered wallet
- compare two extracted strings and get password for the wallet

I have superficial knowledge of cryptography, but this should work :)

my idea is feasible?
Anyone know about software that can do what I described?
Can anyone create such software for reward?

You can't do this anyway. Bitcoin Core uses AES. Read here: https://en.wikipedia.org/wiki/Known-plaintext_attack

Thank you! This is the answer for question