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Cracking Pdf Encryption


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Does anybody know of some tools that can be used to decrypt an encrypted Adobe PDF file? According to acrobat, the Security method is Document Open Password Security with 128-bit AES encryption. I could've sworn somewhere I read the BackTrack4 includes a tool that can help with this, but I can't find that article, nor do I have a BT4 iso at the very moment. If it helps, I have attached a sample file of what would need to be decrypted. The password for it is 2011DecryptTest.

http://ge.tt/39GDd9C

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If the password is weak/short enough you can just brute force it or use a dictionary attack. Like everything you want to attack it at it's weakest point. When it comes to encryption (especially standards like AES) the weakest point is the password (usually). Now if the password is too long 14+ chars. or and uses full ASCII characters like !@#lsa.?< then these attacks won't yield much success for a long time. I used to have a program that did this but a quick google search may find a free one.

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If the password is weak/short enough you can just brute force it or use a dictionary attack. Like everything you want to attack it at it's weakest point. When it comes to encryption (especially standards like AES) the weakest point is the password (usually). Now if the password is too long 14+ chars. or and uses full ASCII characters like !@#lsa.?< then these attacks won't yield much success for a long time. I used to have a program that did this but a quick google search may find a free one.

very true. now to assemble a cluster of 50 PS3's!

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very true. now to assemble a cluster of 50 PS3's!

Woot I'm in! Never updated mine so linux is still there!! :D Now let's crack us some encryption!

EDIT: You could also hope that they didn't implement AES properly and see if there are anyways to recover the password. I think this is what happened with MS Office a while back where the password/keys could be recovered from the file because they used a weaker hash.

Edited by x942
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If you want to crack passwords using a cluster, invest into nvidia graphics card, like the GTX 580s. They have over 500 cores, of parallel processing power and they are more efficient than having over 50 standalone computers.

And to crack PDF passwords, you will need a distributed password cracker like

http://www.elcomsoft.com/edpr.html

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