Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

How can i recover a zip password on linux using CUDA (GPU). For the past two days i tried using "fcrackzip" but it's too slow

Few months back i saw some application that can use GPU / CUDA and get large performance boost in comparison to CPU.

If brute-force using cuda is not possible, please tell me what's the best application for performing a dictionary attack, and where can i find best (largest) dictionary.

Regards

share|improve this question
add comment

2 Answers

According to this article using CUDA for brute-force against ZIP is possible, but I haven't found free app so far. The difficulty of using CUDA for ZIP is that the "forced" attempt is not consisting of a single calculation like in brute-forcing hash, but requires reading the zip file and attempting to decrypt it. To utilize CUDA, you will need to virtualize that process - load the zip in the GPU memory, rewrite the decryption method in code executable by the GPU, evaluate the result dynamically.

Please share if you have found any solution yourself.

share|improve this answer
add comment

Have you tried a precomputed rainbow table?

Unless your password is long or your zip uses special (ie, salted) pass hashing, this should suffice if you're willing to torrent a huge file.

Here are some places you can download.

btw, downloading an ophcrack rainbow table and exposing how weak our critical webapp's hashing was, got my SW manager to agree to have us non-trivially salt our hashes.

share|improve this answer
    
Rainbowtables only work for hashes not for encryption. –  OliverS Aug 13 '10 at 9:29
1  
OliverS, how do you think the encryption works, magic? If the zip is password locked then the goal is to retrieve the password, not brute-force decrypt the entire volume. All password implementations use hashing to match entered with stored password. –  r00fus Aug 15 '10 at 19:54
    
The password to a locked Zip file isn't stored as a hash, it's the key to the encryption algorithm (AES). You can't use rainbow tables to attack the password as you can't recover a hash to compare against. –  Nick Pascucci Jul 13 '11 at 4:07
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.