Password recovery?

[fanya]

Years ago I doomed my Bitcoin. I searched every device and USB from back then and found something.

I have split it into 2 different files. It is 40 characters long, machine-generated and consists only of capital letters and numbers. Unfortunately, I can only find the first file.

I have the first 20 characters. Any chance of guessing the last 20 characters because it consists only of capital letters and numbers?

If it were possible, I could perhaps rent a server. I don't want someone else to do this because I don't want to give away the wallet files. I think you can understand that.

[Findingnemo]

If it were possible, I could perhaps rent a server. I don't want someone else to do this because I don't want to give away the wallet files. I think you can understand that.

It's not possible to brute force the given combination even the entropy reduced due to the availability of 20 characters and the remaining were only uppercase letters.

To find the entropy:

(A-Z) + ( 0-9) = 26 + 10 = 36

Unknown characters = 20

So number of possibilities= 36²⁰.

Even with the most powerful GPU brute forcing this combination will be forever.

Try to look for the remaining half of your backup cause that's the only realistic option to recover your Bitcoin.

[Mia Chloe]

To find the entropy:
(A-Z) + ( 0-9) = 26 + 10 = 36
Unknown characters = 20
So number of possibilities= 36²⁰.
Even with the most powerful GPU brute forcing this combination will be forever.

You do have a nice entropy calculation but you did make an error. That is because basically, private keys are case sensitive, meaning the total number of combinations or permutations rather since "3A" and "3a" or "A3" and "a3" are not the same should be something like:

(A-Z)×2 = 52 ; this is because, number of upper case +  number of lowercase has to be taken into account.
Also the 10 digits (0-9) so in total we have 62 permutations.
To put into simple permutative perspective, we have 62²⁰.

As for the OP you can't run such a brute force because it's like wasted power since the computer will end up running for years. Only the concept of quantum computing may pull it off but it's still not applicable here.

[mocacinno]

@Mia Chloe,

OP said the missing string consists of capital letters and numbers in his first post, Findingnemo's calculations seem correct. You are correct that if the op did not specify this condition, the number of possibility's would have surpassed Findingnemo's calculations.

Anyways, you are both right, bruteforcing this is not possible, odds of finding this in reasonable time are so close to zero, it's better to say they are zero.

[Mia Chloe]

@Mia Chloe,

OP said the missing string consists of capital letters and numbers in his first post, Findingnemo's calculations seem correct. You are correct that if the op did not specify this condition, the number of possibility's would have surpassed Findingnemo's calculations.

I noticed that but I'm a little skeptical about what the OP said because I've haven't really seen a case of all upper case only in a private key.
Do you mind making a little explanation how feasible it is because OP's question looks more like a theoretical based question to me more than an actual regular scenario with private keys.

Basically I made my calculations on the simple concept of permutations taking the case of an actual private key since like I said earlier a regular private key will create more character permutations (by 2²⁰) increasing the time and computational power needed more.

[Findingnemo]

Do you mind making a little explanation how feasible it is because OP's question looks more like a theoretical based question to me more than an actual regular scenario with private keys.

We can generate our own private keys with the specified parameters in multiple ways. Manual methods such as Rolling dice ny converting the results into binary and derive the bitcoin address from it or using the python script

Code:

import random
import string

# Define allowed characters (A-Z and 0-9)
chars = string.ascii_uppercase + string.digits

# Generate a 64-character key
custom_private_key = ''.join(random.choices(chars, k=64))

print("Custom Private Key:", custom_private_key)

and in some other ways since OP mentioned that

It is 40 characters long, machine-generated and consists only of capital letters and numbers

I made my calculations for this scenario but in anyway with or without the lowercase it is impossible to break even if the entropy is around 103 bits.

[Mia Chloe]

We can generate our own private keys with the specified parameters in multiple ways. Manual methods such as Rolling dice ny converting the results into binary and derive the bitcoin address from it or using the python script.

Hmmm... I think I do understand the concept now. Before now I've actually come across other methods of private key generation but now I get the concept why some generation approaches are safer than others. Basically what it simply means is that the OP generated his keys with an algorithm with a lower entropy than regular key generation processes.

I made my calculations for this scenario but in anyway with or without the lowercase it is impossible to break even if the entropy is around 103 bits.

Exactly but I think that means that although OP's entropy of 36⁴⁰ in contrast to 62⁴⁰ is of lower difficulty, still the difference in security level is almost same since both can't be brute forced.

[mcdouglasx]

Years ago I doomed my Bitcoin. I searched every device and USB from back then and found something.

I have split it into 2 different files. It is 40 characters long, machine-generated and consists only of capital letters and numbers. Unfortunately, I can only find the first file.

I have the first 20 characters. Any chance of guessing the last 20 characters because it consists only of capital letters and numbers?

If it were possible, I could perhaps rent a server. I don't want someone else to do this because I don't want to give away the wallet files. I think you can understand that.

1- I suppose you created a kind of brainwallet, composed of 40 characters A-Z 0-9, or a private key(hex) of 40 characters A-F 0-9 (case-insensitive) with 160 bits.

2- You divided these into two .txt files with 20 characters each, and for "security" you separated them by storing them on different devices.

Since you found one of the two files, the most recommended is to meticulously search for the missing file or use data recovery software. For example, if the found file is called btc1.txt, the other one is probably named btc2.txt.

Brute force is not viable because, in the best-case scenario, you used hex, which equals 80 bits of possible combinations.

[fanya]

We can generate our own private keys with the specified parameters in multiple ways. Manual methods such as Rolling dice ny converting the results into binary and derive the bitcoin address from it or using the python script.

Hmmm... I think I do understand the concept now. Before now I've actually come across other methods of private key generation but now I get the concept why some generation approaches are safer than others. Basically what it simply means is that the OP generated his keys with an algorithm with a lower entropy than regular key generation processes.

I made my calculations for this scenario but in anyway with or without the lowercase it is impossible to break even if the entropy is around 103 bits.

Exactly but I think that means that although OP's entropy of 36⁴⁰ in contrast to 62⁴⁰ is of lower difficulty, still the difference in security level is almost same since both can't be brute forced.

I think there has been a misunderstanding here. I am not trying to get my private keys back, but the password to my Electrum file. I also used to store private keys in an encrypted zip file. I was very ignorant back then because there weren't many options yet

I have apparently split the password for these files into 2 files, it looks like. I didn't remember that either. I found Part 1 (first 20 characters).

Here is my old thread, I asked something similar. https://asktom.cf/index.php?topic=5523791.0

[mcdouglasx]

We can generate our own private keys with the specified parameters in multiple ways. Manual methods such as Rolling dice ny converting the results into binary and derive the bitcoin address from it or using the python script.

Hmmm... I think I do understand the concept now. Before now I've actually come across other methods of private key generation but now I get the concept why some generation approaches are safer than others. Basically what it simply means is that the OP generated his keys with an algorithm with a lower entropy than regular key generation processes.

I made my calculations for this scenario but in anyway with or without the lowercase it is impossible to break even if the entropy is around 103 bits.

Exactly but I think that means that although OP's entropy of 36⁴⁰ in contrast to 62⁴⁰ is of lower difficulty, still the difference in security level is almost same since both can't be brute forced.

I think there has been a misunderstanding here. I am not trying to get my private keys back, but the password to my Electrum file. I also used to store private keys in an encrypted zip file. I was very ignorant back then because there weren't many options yet

I have apparently split the password for these files into 2 files, it looks like. I didn't remember that either

Here is my old thread, I asked something similar. https://asktom.cf/index.php?topic=5523791.0

It is still not feasible, Electrum Wallet encrypts the wallet with a passphrase using a symmetric encryption algorithm, specifically AES and in this case A-Z 0-9 [20] brute force against an AES encrypted passphrase is not feasible due to the high complexity and time required.

[BitMaxz]

I think there has been a misunderstanding here. I am not trying to get my private keys back, but the password to my Electrum file. I also used to store private keys in an encrypted zip file. I was very ignorant back then because there weren't many options yet

I have apparently split the password for these files into 2 files, it looks like. I didn't remember that either. I found Part 1 (first 20 characters).

Here is my old thread, I asked something similar. https://asktom.cf/index.php?topic=5523791.0

You mean that you forgot the passphrase of the Electrum backup wallet?
And then you split the password into two files, like a sample "Mypass" saved into a text file, then archive it into a zip file. After that, the second part of the password is "Phrase" saved into a text file again, and archived into a zip.
Meaning you split your passphrase and archive them into a zip file protected with another password, but you forgot the password of these 2 files?

If that's the case, I don't think there's a tool to brute force a zip file. Why not brute force your passphrase instead if the wallet file in your Electrum is still available on your PC?
If you don't remember the whole passphrase or just part of it, the chances that you can brute force this wallet are very slim.

You might need to hire a professional to brute-force this wallet If you seek for professional help, then check this thread below

- https://asktom.cf/index.php?topic=240779.0

[Findingnemo]

[q]I think there has been a misunderstanding here. I am not trying to get my private keys back, but the password to my Electrum file. I also used to store private keys in an encrypted zip file. I was very ignorant back then because there weren't many options yet

I have apparently split the password for these files into 2 files, it looks like. I didn't remember that either. I found Part 1 (first 20 characters).

Here is my old thread, I asked something similar. https://asktom.cf/index.php?topic=5523791.0

So this thread is part of its continuation or is it different matter. Because you said in the previous thread files were in the encrypted ZIP but here's about missing password...

Anyway possibility of brute forcing is same if it's 20 missing chars in pass or private keys but can you make it clear, the private keys are backed up right so it's lost or in your possession? If you have keys you can simply import the address in new wallet irrespective of encrypted Electrum file.