Bitcoin Forum

Hi , I recently set up a bitcoin wallet which i encrypted and I cant remember the passphrase........... I know.......

I can narrow down the characters used to about 20, I know where the only upper case letter is, and i know it can contain only 1 of 4 possible symbols at max.
The password is between 8 and 15 characters.

Would this be possible to brute-force this?

I'd appreciate any help

Thanks

Do you have a backup from before you encrypted it? If yes then you maybe able to use pywallet to recover the private keys for some of your addresses. Google for pywallet.

Wow.. That sucks how many coins were in it?

how many BTC do you have in there?

Some tools to help brute force passwords from partially known ones have been developed on the forum (you might try searching a bit to see if you can find them).

So how do we know your not a hacker tryna steam someones bitcoins?

I have 2 btc in there at the moment, my first time ever buying bitcoins , bad start to the whole bitcoin scene

I tried the script posted in this forum already but its not really what im looking for, is there any commercial pieces of software out there?

If I was a hacker I would have to bruteforce the password with no information which apparently is impossible

. Ok i believe you.

hu, save the wallet with several copies .. who knows, is possible you type the password tomorrrow or a few days.

Ill keep trying that, dont think its going to happen though. No ideas so?

Best of luck with this but with a password of that length the odds of a brute force hack are stacked against you. :)

What bitcoin client did you use to encrypt? bitcoind? or did you use a gui client?

bitcoind

@drbanjo, I second this. Save the wallet for sometime in the future when the password comes back to you... hey maybe you can see a hypnotherapist to have the password recovered from your brain?

Did you use bitcoind on a linux console? Perhaps the passphrase is still in your bash history?

Windows unfortunately, is there some way to read the keylog ?

I dont think ill remember it, its a password i never used before and I dont think i ever really learned it off, I just presumed it was so easy I wouldnt forget it! haha................... :'(
 

To brute force a password that is 15 characters (assuming it has numbers, lower, and uppercase letters would take forever, literally:

Time Required to Exhaustively Search this Password's Space:
Online Attack Scenario:
(Assuming one thousand guesses per second)   2.48 hundred trillion centuries
Offline Fast Attack Scenario:
(Assuming one hundred billion guesses per second)   2.48 million centuries
Massive Cracking Array Scenario:
(Assuming one hundred trillion guesses per second)   2.48 thousand centuries

I'd better get started so

I know nothing about windows, but it would be worth searching some windows related forums in order to determine if the pass phrase you typed is stored in a history somewhere; for instance, bash will store everything typed on the command line to an in-memory history that is searchable, and then it will also save that history to disk when you exit the terminal.

Also, if you can find a way to remember the length of the pass phrase, and maybe even recall some more of the characters, you may be able to get it down to few enough combinations that it can be brute forced.

I would think that could be quicker based on some of the things that the OP said they know. If you use an offline very fast set of computers I would say you could get it (hopefully in a few years tops:))... is it worth it depends on how many coins in it.

well its max 15 charachters long, only 1 capital letter , only 1 symbol if even. Only 20 character's possible in the set

See here:
https://bitcointalk.org/index.php?topic=85495.0 (https://bitcointalk.org/index.php?topic=85495.0)

If you can remember "most" of it, you should be able to get into it.

If the worst happens you only have 2 BTC in there so you could put it down to experience and move on, (but I would hate doing that as well.)

$250 is one expensive lesson

With a passphrase made up of 8 random characters drawn from a set of 24 possible characters (20 + 4 symbols) you are looking at 110,075,314,176 possible combinations.

I'm not certain, but that might be possible.  Even better if you know that there is definitely one and only one symbol in the passphrase. Better yet if you can remember any specific characters that were definitely in the passphrase, and much better if you can remember any specific locations of any of hose characters that were definitely in the passphrase.

Really, the more you can remember about the passphrase, the easier brute forcing becomes.  Remember a sequence of 2 or 3 characters that were definitely somewhere in the passphrase (such as "ed3k"), and you chances start to look really good.  Remembering the length to a better specification than "between 8 and 20 characters" would help a lot as well.

Now, if you are looking at a passphrase made up of 15 random characters drawn from a set of 24 possible characters, you are looking at about 504,857,280,000,000,000,000 possible combinations.  This is MUCH MUCH less likely to be brute forcible if you can't remember much else about the passphrase.

Wow, you really remember almost nothing about it, do you? You can't even remember if there was a symbol in it or not? Sounds like total amnesia.

Sorry, didn't see this post until after I made my previous.

So it's definitely 15 characters?  That's going to make it tough unless you can remember more about it.  It helps that a symbol only occurs once, but even ignoring the potential symbols for the moment, just the fact of 15 characters drawn from a set of 20 possible is probably more than you are going to reasonably brute force.  Perhaps some meditation and visualization will help you recall more facts about the passphrase?

I experienced the same problem before. My advice to you is try to remember the password. Think in a simple/easy way, do not make the situation worse by trying to remember more complex passwords that you would have used. I remembered my password away from the computer/keyboard. Trying multiple failure passwords would make it much harder for you to remember. Good Luck!

Well Im certain its either a typo in a password I use for everything or else its something quite easy, which would have one capital and only one numeral which I know at the end and only uses alphabetic characters(all lower case except for the one capital), eitherway I think I remeber the first 5 or 6 characters at least. Im sure I could narrow it down more, would I have to script my own brute-force app or is there something I can use?

I reckon if I had the right software I could play around with the parameters to get it.

Thanks for all the replies, appreciate it!

You got a lot of help on this thread, you should be able to retrieve it if u know some of it

Have you recoved it yet?

Nope, just got home , ive been trying everything possible but I think im starting to confuse what I had remembered with what I've being trying

Id almost give out my .dat just out of interest to see if anyone can hack it, doubt ill be able to get it open

Stop trying.  You'll only confuse yourself more and make it harder to remember.

Start by assuming that the coins are gone for good and coming to grips with the loss.  Hoping that you can recover them is increasing your anxiety at the possibility, and delaying the process of overcoming panic.

Next sit in a quiet room.  Turn on some of your favorite music.  Get a pen and paper.  Try to clear your mind of any other concerns you have right now.

Think back to the date and time when the password was entered.  Don't try to remember the password.  Don't try to remember anything you were doing with your wallet. Think about other things you were doing at that time.  Where were you sitting? What time of day was it? What was the weather like? Was the TV on?  Was there anyone else around?  Scent is strongly linked to memory.  Was dinner cooking? Were you drinking coffee? Was someone wearing perfume/cologne nearby?  What had you been doing before you started messing with your wallet?  What did you do after you finished messing with your wallet?

Now that you've got your mind focused on the day and time and various memory triggers surrounding the wallet, close your eyes and think out what you saw on the screen.  Can you visualize any of it?  Where on the screen was your wallet located?  What other programs (if any) did you have open at the time?  Picture the window for entering your password as best you can remember it.

Now, what fuzzy things do you remember about the password?  Approximate length, sounds or letters that caught your attention.  ("there's a z in there? huh, that's unusual", "trmp, hmm, that almost looks/sounds like tramp", etc).  What specifics do you remember.  (First letter?  First 2 letters?  Last letter?  Last 3 letters?,  "It definitely has the following letters somewhere in the middle.", "I remember these 2 (or 3) letters were all together in this order.").

Write down whatever you can remember.  Get it on paper so that later when you are trying variations you don't mix up what you remembered with what you tried.

Once you've spent some time relaxing, focusing, visualizing, and writing, get some sleep.  Go to bed and drift off while thinking about what else if anything you can remember about the password.  Keep paper and pen next to the bed.  When you wake up (in the middle of the night and/or in the morning) think for a moment about your password and if there is anything new you remember about it.

Now take that paper and use the information from it to configure a brute force script (there are a few good ones in the forum, you can search for them or write your own).

The more information you can remember the more likely you are to reduce the possibilities to something that can be brute forced.  Just remembering the position of a single additional character can make a HUGE difference in the amount of effort necessary.  It you can't write or configure a script on your own, find a trusted member of the forum who can help you.  There are several well trusted members with both the ability and interest in helping you get a script up and running if they think there is a possibility of recovering the password with the info you can provide.

There are even some who you can trust with your wallet.dat who will run the script for you and send you the bitcoins if they succeed.

To add on to this, don't let your fear of loss bother you. Fear causes chemical reactions in the brain that causes decreased thought ability ("fight or flight"). It's the same problem a lot of people have with tests.

Just let it go and occasionally it will come back to you (or should).

The more you work yourself up about it the harder it's going to be to remember.

I don't know what to tell u man, hope you get it solved. Thats the problem with passwords for stuff like this you can forget whenever. just like people here recommend having an offline bitcoin address, I have an offline computer where i keep all my passwords offline and off the net. Best bet is just ot have a usb drive/harddrive/sd card with an os and the information and keep it hidden in your house. that way someone has to physically go to your house, locate that usb/sd card, launch it, etc.

This is HORRIBLE advice.  Please, please, nobody take this advice.  If you are going to do this, then don't even bother encrypting your wallet.  You'll just give yourself a false sense of security and be more likely to engage in actions that will compromise your wallet.

Thanks for the advice, ill try forget about it for the meantime and then try recreate the situation.

Good luck retrieving your coins!

https://www.dropbox.com/sh/nl2eryt1mqb3ws7/NzBQv_0eY8

Have a go, Theres actually only 1.1 BTC in the wallet, Im positive the first word of the password is 'Hello' with a capital H , the last charachter is a 1, everything in between I havent a clue, one or two words I reckon. If anyone gets it I'd love to know what the password was and if your feeling exceptionally generous you could give me some of my money...  Anyway enjoy , ask any questions you want re: password

The number of characters between the "Hello" and the "1"?  Are you certain that there is more than one character?  Can you say with certainty that there are more than 3?  How about 5?

Same question on the high side.  Definitely less than 100 characters?  Less than 25 characters? Less than 10?

Specifically what I'm asking is what is the smallest range of quantity of characters that you can say there are with certainty between the "Hello" and the "1"? (Positively more than 1, and less than 100, but can we narrow it down a bit more than that?)

Question 2.

Can you say with any certainty what type of characters definitely exist between the "Hello" and the "1"?

Upper case?
Lower case?
Numeric?
Symbols?
Spaces?

Can you say with any certainty what types of characters definitely do NOT exist between the "Hello" and the "1"?

Upper case?
Lower case?
Numeric?
Symbols?
Spaces?

Do you have a set of words that you think you'd be likely to use?

Is there any type of word you are likely to use or to avoid?

Peoples names?
Animals?
Technical concepts?
Hobbies?
Colors?
Verbs?
Objects?
Adjectives?
Vulgar words?
Stuff from your every day life?
Medical words?
Something Cherished?
Etc.

1. I reckon its between 4 and 8, again I cant remember if im remembering failed password attempts or the original, I can guarantee its less than 15 though , i would never use a password that long,

2. Everything is lower case after the first capital, there may be a slight chance there is a #  before the 1 but I doubt it

3. Regards to words: chronic, number , everyone, everybody, one (I was really high when I did this so its something stupid and easy I think)
I reckon if you were going to try you would be better off using a dictionary attack if these words dont help you

I'll take a stab at it. Can't make any promises.
I'll let you know.

if you are unable to brute force it now consider that you may be able to at some point in the future. write down everything you can remember somewhere safe and save the encrypted wallet somewhere safe. Then someday if your 2 bitcoins are worth 200,000 dollars you can rent some serious computer power in an attempt to crack it.

Error: wallet.dat corrupt, salvage failed

Are you sure you sent us the right file? I'm not sure what's up with it.

Definitely, I was just trying to reduce the number of words in the "dictionary" that would need to be used.  Also, if you were "really high", then there's a pretty good chance that you misspelled the words you used.