Is PDF real Secure?

ElcomSoft said,

Here is what I was able to easily achieve, in mere seconds, on a regular PC.

1. Remove the Master Password and all the restrictions** it controls.
2. Remove the User Password*** (File Open), 40 and 128-bit RC4 encryption.
3. Remove DRM security from a PDF eBook that was locked**** to my system, and revert this PDF eBook to a regular PDF file that can be viewed and edited in Acrobat.

PDFCrack–RubyPDF supplies free software to get the PDF User Password, support 40 and 128-bit RC4 encryption, and 128 AES encryption, it is open source, and supports multiply plantform, the windows version is compiled and suppiled by RubyPDF.

PdfCrypt–RubyPDF also supplies free software to remove the PDF Master Password with need it, and the PDF User Password with the PDFCrack helps.

If you lost orgianl uncrypted PDF,  but want to remove Certificate Encrypt PDF, you can also ask RubyPDF for help.

Recovery PDF Password with Free software PdfCrack

PDFCrack is a GNU/Linux (other POSIX-compatible systems should work too) tool for recovering passwords and content from PDF-files. It is small, command line driven without external dependencies. The application is Open Source (GPL).

Features

• Supports the standard security handler (revision 2, 3 and 4) on all known PDF-versions
• Supports cracking both owner and userpasswords
• Both wordlists and bruteforcing the password is supported
• Simple permutations (currently only trying first character as Upper Case)
• Save/Load a running job
• Simple benchmarking
• Optimised search for owner-password when user-password is known

Here are some person talk about pdfcrack,

1. PDFCrack | RubyPdf Technologies

2. PDFCrack 0.11 for Window Releases | RubyPDF Blog

3. Free PDF Password Recovery for Windows