Pretty Good Privacy (PGP) is a data encryption and decryption computer program that provides cryptographic privacy and authentication for data communication. PGP is often used for signing, encrypting, and decrypting texts, e-mails, files, directories, and whole disk partitions and to increase the security of e-mail communications. PGP and similar software follow the OpenPGP standard for encrypting and decrypting data. OpenPGP's encryption can ensure secure delivery of files and messages, as well as provide verification of who created or sent the message using a process called digital signing. Using OpenPGP for communication requires participation by both the sender and recipient. OpenPGP can also be used to secure sensitive files when they're stored in vulnerable places like mobile devices or in the cloud.