PDF Password Cracker can be used to decrypt protected Adobe Acrobat PDF files, which have "owner" password and "user" password set. It has Key search attack, which guarantees the decryption of PDF files that use 40-bit encryption. PDF Password Cracker recovers user password required to open the file. Brute-Force or Dictionary attacks are used to recover the user password in PDF Password Cracker software. It needn't Adobe Acrobat software.