Wallet Encryption Password Lost - 10 BTC!

[guitarplinker]

I've messaged Dave via the service and said I would happily pay him, no reply yet.
I had a thought, if I export the dat as a .txt, then change the encrypted private key to a new one that I know, then export to a .dat
Would that work? Like overwriting the original encrypted private key?

That wouldn't work. If you changed the encrypted private key to a new private key with a new password, you would lose access to your old encrypted private key holding the 10BTC worth.

One thing you can do though if you can't figure out the password is keep the wallet.dat file safely backed up for a long time - I'm sure that in 10 or 15 years it'll be much easier to crack a 30-40 character password than it is now with faster computing, plus there's always a chance that the encryption algorithm for Bitcoin-Qt will be cracked. That'll definitely be a long time from now, but it might be worth it.

[redsn0w]

I've messaged Dave via the service and said I would happily pay him, no reply yet.
I had a thought, if I export the dat as a .txt, then change the encrypted private key to a new one that I know, then export to a .dat
Would that work? Like overwriting the original encrypted private key?

That wouldn't work. If you changed the encrypted private key to a new private key with a new password, you would lose access to your old encrypted private key holding the 10BTC worth.

One thing you can do though if you can't figure out the password is keep the wallet.dat file safely backed up - I'm sure that in 10 or 15 years it'll be much easier to crack a 30-40 character password than it is now. That'll definitely be a long time from now, but it might be worth it.

Yeah , I think this is the unique solution for the moment. With the technology of the future maybe you can easily crack the password (but I'm not sure).

[CryptKeeper]

I've messaged Dave via the service and said I would happily pay him, no reply yet.
I had a thought, if I export the dat as a .txt, then change the encrypted private key to a new one that I know, then export to a .dat
Would that work? Like overwriting the original encrypted private key?

That wouldn't work. If you changed the encrypted private key to a new private key with a new password, you would lose access to your old encrypted private key holding the 10BTC worth.

One thing you can do though if you can't figure out the password is keep the wallet.dat file safely backed up - I'm sure that in 10 or 15 years it'll be much easier to crack a 30-40 character password than it is now. That'll definitely be a long time from now, but it might be worth it.

Yeah , I think this is the unique solution for the moment. With the technology of the future maybe you can easily crack the password (but I'm not sure).

The bitcoin-qt uses key stretching for the encryption of the wallet.dat. Somewhere in the wallet.dat is an entry about the number of rounds that are needed for decryption of the private keys. Depending of the speed of the pc which encrypted the wallet.dat it can be 100000 or more rounds of AES256. It's done in this way so that even passwords of short length are very hard to break by brute force!

TL;DR
If you have one or two typos in your password, it could be possible to brute force it. But 30-40 characters are not crackable for a very long time. 

[casperround]

Well this seams like a dead loss.
Has anyone tried the change passphrase option on Pywallet?

[CIYAM]

Well this seams like a dead loss.

Are you seriously saying you think that your wallet is encrypted with a 30-40 character password of which you can't remember any of it?

(because if that is what you are saying then I would be seriously doubting that it actually is your wallet at all)

[guitarplinker]

Well this seams like a dead loss.

Are you seriously saying you think that your wallet is encrypted with a 30-40 character password of which you can't remember any of it?

(because if that is what you are saying then I would be seriously doubting that it actually is your wallet at all)

He could have generated a password in KeePass or similar, and then forget to save KeePass once he had the password generated, losing access to the wallet. I use KeePass and I know a couple of times I've almost shut off my machine without saving my new KeePass entries.

[casperround]

Well this seams like a dead loss.

Are you seriously saying you think that your wallet is encrypted with a 30-40 character password of which you can't remember any of it?

(because if that is what you are saying then I would be seriously doubting that it actually is your wallet at all)

Reason it's my wallet, I use a 30-40 character password for most of my bitcoin accounts, with upper case, lower case, and numbers to stop people from taking from me. As I have already have an incident where someone stole 1.2Btc from my Blockchain wallet!

[CIYAM]

He could have generated a password in KeePass or similar, and then forget to save KeePass once he had the password generated, losing access to the wallet. I use KeePass and I know a couple of times I've almost shut off my machine without saving my new KeePass entries.

Indeed - now that you have given him an explanation I'm sure he'll use it (I was actually trying to see if he would come up with such an explanation himself).

Doh!

(maybe next time you might consider waiting before feeding people answers)

[casperround]

He could have generated a password in KeePass or similar, and then forget to save KeePass once he had the password generated, losing access to the wallet. I use KeePass and I know a couple of times I've almost shut off my machine without saving my new KeePass entries.

Indeed - now that you have given him an explanation I'm sure he'll use it (I was actually trying to see if he would come up with such an explanation himself).

Doh!

(maybe next time you might consider waiting before feeding people answers)

I actually wrote that before, although the forum said (While you where writing a reply, a member has commented. You may want to read that before posting a new reply)

So in future maybe you shouldn't be so ignorant!

[CIYAM]

So in future maybe you shouldn't be so ignorant!

If I missed that you explained you were using Keepass then it seems so did a few others (although I notice something in the OP now which I don't recall seeing before).

Very strange that you would say you "forgot" your 30-40 character password anyway - if you were using a tool then you would never have "remembered" such a password in the first place.

There have been a few newbies before wanting to work out how to crack encrypted wallets that looked rather suspicious (hence my question).

In any case as has been pointed out 30-40 unknown characters is not going to be able to be cracked.

[btchris]

Does anyone know any bruteforce programs for the wallet.dat, that can use a GPU?

btcrecover, which I mentioned above, does support GPU-accelerated password searches for wallet.dat files (or for dumpwallet.py files like you also partially posted above).

It's still pretty unclear (to me anyways) if this is a password you remember most of, or if it's a KeePass or similar password which you don't have any of. If it's the latter, and if it's a complex as you've stated, than there's absolutely zero chance you'll ever be able to recover it without recovering it from KeePass.

Here's a link to the time it would take to brute-force a random 30-character long password (upper + lower + digits) using 4 high-end GPUs.

[Sellers]

30-40 characters password is long

[SpreadBit]

Your wallets final balance is 0 BTC.

[Haruko]

Your wallets final balance is 0 BTC.

just to let you understand...

try to browse this site

http://projects.lambry.com/elpassword/

and you will understand who you wallet it is uncrackable!!!

[Hash72]

Your wallets final balance is 0 BTC.

just to let you understand...

try to browse this site

http://projects.lambry.com/elpassword/

and you will understand who you wallet it is uncrackable!!!

Good advise but more security need you to have more than one recovery options specially for this amount of BTC good luck

[redsn0w]

#OP , I think it will be impossible for you to recover your bitcoin , I'm sorry for that and I suggest you the next time to use another *system of security* .

[syahrere]

omg 20btc 
next time u must care with security for ur BTC wallet 

[SpreadBit]

Wallet doesn't have any amount.

[Anillos2]

Yep thats the reason I do not want to lose that amount.

The password is around 30-40 characters with uppercase/lowercase/numbers

Next time write it in paper...

[Welsh]

Unless you know the majority of your password no one will be likely to help you, 30 characters of unknown characters is a huge amount for a program to brute force. The amount of the users who come to me only know about a quarter to half of their password and that's normally not enough.