Decrypt protected Adobe Acrobat PDF files, which have "user" and/or "owner" passwords set, preventing the file from opening or editing, printing etc. If only "owner" password is set, password recovery is not needed at all, but the file is being decrypted instantly. "User" password can be recovered using brute-force and dictionary attacks; also, the program supports "key attack" that allows to decrypt PDF 1.3 files regardless the password length.