Guaranteed PDF Decrypter

PDF decryption utility
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PDF Permission password removal

PDF Open password removal

  
 
Purpose
The primary goal of Guaranteed PDF Decryptor (GuaPDF) is to remove restrictions on any PDF document (you should have the right to do it, for example, if you forgot the password).

 This version of GuaPDF can also be used for remove the PDF open password. Decryption of the file with password for opening is guaranteed for PDF files with 40-bit key only (Acrobat 3, 4 compatible encryption). This process takes several days on one home computer and distributed cracking is also supported.
Only standard PDF security is supported, neither third-party plug-ins nor e-books.

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

PDF security overview

The standard security of PDF documents can have two different of passwords: a Document Open password and a Permissions password. When a Document Open password (also known as a user password) is set, anyone who tries to open the PDF must type in the password. When a Permissions password (also known as a master password) is set, recipients don't need a password to open the document, but they must type the Permissions password to set or change the restricted features. If the PDF is secured with both types of passwords, it can be opened with either password, but only the Permissions password allows the user to change the restricted features.

Used crypto algorithms were being improved with PDF developing - up to version 1.4 only 40-bit keys have been used, then the 128-bit ones came, and starting from version 1.6, AES encryption is being added. A document with password for opening, using 40-bit key, can be decrypted by GuaPDF on Core 2 Duo 6300 within three days. To open a document with 128-bit key, only brute force search for password can be used.

Method to decrypt files with password for opening (Acrobat 3.x, 4.x only)

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 20 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, 4 scheme and Acrobat 5-8 40-bit 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 240 keys to decrypt your file with guarantee. GuaPDF does it, and key testing will take about 3 days on the Core 2 Duo E6300 PC. Within this time (and on average within half of time) ANY file, encrypted with ANY password (no matter what the length of the password is or what language or symbols are 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.

Versions and Price
The best way to choose which version you need is to run DEMO.

There are some GuaPDF versions for files protected with password for opening:
  • 2,5-CLIENTS. These versions process both security methods (i.e. open and permissions passwords), have supports for multiple processors/cores and for distributed clients which number are limited. (from €/$39)

All these version are licensed for non-commercial purposes only. If you wish to use GuaPDF to make any profit you should use
  • UNLIMITED, most powerful version. It does everything, has no limitations. (€/$150)

 
Version Restrictions (or permission password) removal,
Acrobat 3.x-8.x up to 128 bit key		 Key searching Decryption using found key (user password removal) Distributed mechanism

 License Average time to decrypt (on Core 2 Duo E6300) Price
 RC4 encryption (40 and 128 bit key)  AES encryption (128 bit key) Acrobat 3.x, 4.x, 40-bit key
 
Dual version Instantly Instantly YES YES NO (single computer) Non - commercial 3 days (on 2 cores) €/$39
5-clients Instantly Instantly YES YES YES, 5 clients max. Non - commercial 1 day (on 5 clients) €/$49
Unlimited Instantly Instantly YES YES YES, any number of clients Any purposes (except distribution) Depends of number
of clients		 €/$150
 
 
 
Order and download

 
GuaPDF v. 2.3 DEMO for Win32, GUI version (140K)
GuaPDF v. 2.3 DEMO for Win32, command-line version (70K)
GuaPDF v. 2.22 DEMO for Linux (ELF, static, 220K)
GuaPDF v. 2.2 BETA DEMO for Solaris/SunOS (ELF, static, 150K)
 


Please test your file before purchasing

Order the commercial versions over the Internet worldwide using secure connection. This means no one can intercept your confidential information. (Please note I also don't have an access to this information because card will be charged by ordering services listed below). The temporarily link to the fully functional version you receive immediately after verifying your order. Normally you'll get the program within 10-15 minutes.

 
 
 
Customer's FAQ
Q: What version should I choose?
A: Just run DEMO version and it will print it. Briefly, if you can open PDF file, but can not print, edit etc, get the restriction remover version. If you can't even open file, get n-clients version.

Q: I've tested GuaPDF on my file, but got only blank pages (or some errors)
A: It is DEMO version, it can process small files only.

Q: Ok, but how can I sure the full version will work on my file?
A: If DEMO parses your file with no errors, the full version will work fine.

Q: Ok, how long will it take?
A: Restriction removal is instant (may be few minutes on very large files). To estimate key searching time, run DEMO version (and divide it to the number of your PCs).

Q: Are non-standard security handlers supported?
A: No, please run DEMO to make sure your file is supported.

Q: Freeware version found the key, but due to limitations couldn't decrypt the file. Is there the way for not searching for key again?
A: Sure, you'll be able to run commercial version with appropriate parameter.

More questions and answers you'll find in the included documentation. 		 
 
  Last updated: 24 Dec 2006 © Pavel Semjanov, 2000-06