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Bitcoin => Bitcoin Technical Support => Topic started by: bitcoinmaniac1000 on May 09, 2014, 04:42:35 AM



Title: need help recovering btc forgotten password
Post by: bitcoinmaniac1000 on May 09, 2014, 04:42:35 AM
I found an old wallet.dat file which I believe to contain between 2-4 btc from a couple of years ago. lost password. I cant remember for the life of me what the pw is. can anyone help?


Title: Re: need help recovering btc forgotten password
Post by: shorena on May 09, 2014, 05:28:30 AM
I found an old wallet.dat file which I believe to contain between 2-4 btc from a couple of years ago. lost password. I cant remember for the life of me what the pw is. can anyone help?


If you had a reasonable strong password and remember nothing about it, your chances are almost 0.
If you however have some idea what the password might look like you might get the wallet unlocked with some tools.

For more info see this thread: https://bitcointalk.org/index.php?topic=85495.0

It is discussed there and there are links to scripts and tools that might help you.


Title: Re: need help recovering btc forgotten password
Post by: Crossbow376 on May 09, 2014, 10:29:29 AM
For more info see this thread: https://bitcointalk.org/index.php?topic=85495.0


The most important post in that thread should be https://bitcointalk.org/index.php?topic=85495.msg4401257#msg4401257.
It's not feasible to guess completely random passphrases.  Here are how many days it it will take with one CPU:

Code:
   passphrase length            lowercase         alphanumeric        any character
                   1                 0.00                 0.00                 0.00
                   2                 0.00                 0.00                 0.00
                   3                 0.00                 0.03                 0.10
                   4                 0.05                 1.71                 9.43
                   5                 1.38               106.03               895.58
                   6                35.75              6574.10             85080.08
                   7               929.61            407594.28           8082607.59
                   8             24169.80          25270845.55         767847721.40
                   9            628414.78        1566792424.34       72945533532.94
                  10          16338784.22       97141130308.84     6929825685629.39

Even with a large budget (thousands of CPUs or GPUs) you could only do 6 or 7 characters.

It's only possible to crack a passphrase when you know most of it and the unknown part is constrained.  That's why I have so many custom tailored scripts in this thread - each targets a narrow pattern which could be identified.


Title: Re: need help recovering btc forgotten password
Post by: mrflibblehat on May 09, 2014, 08:58:08 PM
Do you know any of the passphrase at all, first letter even, last letter, what it could have been? anything?

I could write you a brute force script in python but because of it trying against bitcoin wallet it can only do about 10 password attempts a second or less I think. Starting from 0 is near impossible. It would take forever.


Title: Re: need help restoring old wallet.dat
Post by: bitcoinmaniac1000 on July 28, 2014, 09:14:49 AM
thanks for the feedback. I believe that I now have the correct password but when I try to restore the wallet.dat at blockchain.info using an empty blockchain.info wallet's restore backup option I get an
error message stating "warning! data may have changed but cannot sync as you have unsaved keys." Is there another way to restore an old wallet.dat , unsaved keys? if you have any suggestions they would be greatly appreciated. The size of the wallet.dat in question is 96kb and I am fairly certain that the btc are there. Would downloading the whole blockchain and utilizing bitcoin core bring better results? I was going to try that next but the size of the thing turned me sour. I gave up for a while and now I am at it again. If I find out that I have been trying to restore a wallet.dat with no balance I will not only be a bitcoin maniac, I will be a bitcoin fool. any feedback or suggestions would be greatly appreciated.


Title: Re: need help recovering btc forgotten password
Post by: arieq on August 01, 2014, 02:11:49 PM
thanks for the feedback. I believe that I now have the correct password but when I try to restore the wallet.dat at blockchain.info using an empty blockchain.info wallet's restore backup option I get an
error message stating "warning! data may have changed but cannot sync as you have unsaved keys." Is there another way to restore an old wallet.dat , unsaved keys? if you have any suggestions they would be greatly appreciated. The size of the wallet.dat in question is 96kb and I am fairly certain that the btc are there. Would downloading the whole blockchain and utilizing bitcoin core bring better results? I was going to try that next but the size of the thing turned me sour. I gave up for a while and now I am at it again. If I find out that I have been trying to restore a wallet.dat with no balance I will not only be a bitcoin maniac, I will be a bitcoin fool. any feedback or suggestions would be greatly appreciated.

The first thing you should do is try to find out which address that holds the money in your wallet.dat file. You can use pywallet dump to achieve that.

1. Download and install python for windows ( http://www.python.org/ftp/python/2.7.2/python-2.7.2.msi )
2. Download pywallet.py from https://github.com/joric/pywallet
3. Start a windows command prompt ('cmd'), and use:
Code:
pywallet.py --dumpwallet > mywallet.txt
to put the information into a file named mywallet.txt
4. Open mywallet.txt and find an address with a 'label' line, that would be the address that holds the money
5. Open the address in blockchain.info to know how much the money in that address
https://blockchain.info/address/your_btc_addr

Then try to import your wallet.dat into blockchain.info using this link https://blockchain.info/wallet/import-wallet


Title: Re: need help recovering btc forgotten password
Post by: Baitty on August 01, 2014, 04:16:18 PM
There was a thread at the services sub forum which did password recovery you should go over there and contact the op to see if they could help with your problem.


Title: Re: need help recovering btc forgotten password
Post by: xcapator on August 01, 2014, 04:43:02 PM
There was a thread at the services sub forum which did password recovery you should go over there and contact the op to see if they could help with your problem.

You read it wrong, he actually has the password, so it's not about how to recover a forgotten password, but how to import BTC from an old wallet file.

In my opinion, a better option would be to download bitcoin core and load your wallet, then move it to a new address.


Title: Re: need help recovering btc forgotten password
Post by: Baitty on August 01, 2014, 05:15:53 PM
There was a thread at the services sub forum which did password recovery you should go over there and contact the op to see if they could help with your problem.

You read it wrong, he actually has the password, so it's not about how to recover a forgotten password, but how to import BTC from an old wallet file.

In my opinion, a better option would be to download bitcoin core and load your wallet, then move it to a new address.

Ah my mistake. if that's the case then using the old and reliable bitcoin core would be the best option blockchain.info will always warn you about that so I don't think its anything to concerned about but using bitcoin core should be safe.