Recover corrupt annotations in some PDF files. Optimize the decryption speed for large PDF files. Optimize the processing for special PDF forms. Provide command line application for manual use or inclusion in scripts. Batch operation on many files from command line. Unlike most PDF password crackers, your PDF file is not altered in any way except the decryption, even the file size is often the same. That minimizes the possible incompatibility of the unlocked PDF file. Brief introduction to PDF password The standard security provided by PDF has two different passwords user passwords and owner passwords. A PDF document may be protected by a password for opening user password and the document may also specify operations that should be restricted even when the document is decrypted printing copying text and graphics out of the document modifying the document and adding or modifying text notes using owner password.