This program (Advanced PDF Password Recovery, or simply APDFPR) can be used to decrypt protected Adobe Acrobat PDF files, which have "owner" password set, preventing the file from editing (changing), printing, selecting text and graphics (and copying them into the Clipboard), or adding/changing annotations and form fields (in any combination). Decryption is being done instantly. Decrypted file can be opened in any PDF viewer (e.g. Adobe Acrobar Reader) without any restrictions -- i.e. with edit/copy/print functions enabled. The program is also able to convert Kinko's Document Format (KDF) files to PDF files (without any protection).

Please note that APDFPR doesn't work with documents which have user-level passwords (preventing the files from being opened), if both user and owner passwords are unknown; and PDF files protected with any 3rd party security plug-ins.

Professional edition also allows to search for "owner" and "user" passwords with brute-force and dictionary attacks, effectively optimized for speed (however, don't expect to recover long passwords in a resonable time with these attacks). In addition, it has Key search attack, which guarantees the decryption of PDF 1.3 files (Acrobat 4.x or older) regardless the password length, by trying all possible 40-bit encryption keys (it takes about 3-4 days on modern dual-CPU systems).

Warning: APDFPR does NOT work on Mac computers with Virtual PC ; unfortunately, it seems to be a problem of Virtual PC itself. However, APDFPR seems to be working just fine on SoftWindows from FWB Software ; you can also try RealPC from the same company.