PDF Password Cracker Professional edition 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 reasonable time with these attacks). In addition, it has Key search attack, which guarantees the decryption (regardless the password length and complexity) of PDF files that use 40-bit encryption (the attack takes about 3-4 days on fast CPU systems).
The standard security provided by PDF consists of two different methods and two different passwords. Owner Password allows to prevent PDF file from printing, editing (changing), selecting text and graphics (and copying them into the Clipboard), or adding/changing annotations and form fields; User Password locks the file so the password is required to open or view the file. If only owner password is set, decryption is being done instantly; decrypted file can be opened in any PDF viewer (e.g. Adobe Acrobat Reader) without any restrictions, i.e. with edit/copy/print/annotate functions enabled. Alternatively, owner password can be recovered using brute-force or dictionary attacks.
Additionally, PDF Password Cracker Pro supports "key search" attack that allows to decrypt (in a reasonable time) PDF files with 40-bit security regardless the password length, guaranteed.
