Guaranteed PDF Decryptor (GuaPDF)

This is a utility that allows you to bypass the security on PDF documents. Both protection methods are cracked:

* restricted operations on file can be disabled (instantly, any Acrobat version up to 6.x, even with 128-bit encryption)
* password encrypted file can be decrypted (in a several days or weeks, Acrobat ver. 3.x, 4.x, 40-bit key)

It also can be used to decrypt files you know password for.

This is GUI utility for Win32 and command-line utility for Linux.

Most password crackers are trying to determine right password by testing passwords (using brute-force or dictionary attacks). This method is good only for short and non-complex passwords. To find 8-character password consisting of lowercase Latin letters and digits you'll need about 50 days. But what if password is longer or consists of special characters or national symbols?

(Un)fortunately, another method to decrypt PDF files exists. PDF security (including Acrobat 3.x, 4.x scheme and Acrobat 5.x-6.x default encryption) uses strong enough encryption algorithm, but because of U.S. crypto export regulations the key length is only 40 bits. So, you need to test only 2^40 keys to decrypt your file with guarantee. GuaPDF does it, and key testing will take about 13 days on the Pentium IV/1600 PC. Within this time (and in average within the half of this time) ANY file, encrypted with ANY password (no matter what length of the password is or what language or symbols used, etc) can be decrypted.

Moreover, GuaPDF offers distributed computing mechanism (via the shared directory) and you should divide the necessary time to the quantity of PCs you've got.

Advantages of GuaPDF are:

* Guarantee of decryption
* New PDF 1.5 (Acrobat 6.x files support)
* Very high speed (optimized for Pentium 4, Pentium II/III, Celeron architecture)
* Confidentiality (you crack your secret files, not someone from cracking service)
* Version for individual user and network version to use power of distributed clients
* Portability (DOS, any Windows and Linux versions are available)
* Running in GUI and keeps running in batch mode (as command-line utility)