PGP Desktop (Pretty Good Privacy Desktop) is a comprehensive suite of encryption and decryption applications that provide cryptographic privacy and data authentication. This suite of applications protects the confidentiality of data stored on a computer disk when the program is not active and provides pre-boot authentication to unlock the encrypted disk. The encryption process makes use of a serial combination of data compression, hashing, symmetric-key cryptography and public-key cryptography, with each public key bound to a single user or email address. It supports message integrity checks that detect whether a message has been altered, and authentication through verification of digital signature to determine if the correct sender sent the message. It is often employed for signing, decrypting and encrypting files, texts, emails, directories, and whole disk partitions to increase the security of email communications. This application can be used on laptop and desktop computers as well as USB or other external drives.