Pretty Good Privacy

PGP software is used to encrypt/protect email as it moves from one computer to another. PGP, is the name of a computer program created in 1991 by Phil Zimmerman.  This program provides cryptographic privacy and authentication — data encryption and decryption — for data communication.  This computer program is commonly used to increase email security by encrypting and decrypting texts, emails, files and directories.

To secure data, this program utilizes a public key system. In the system, each PGP user has a publicly known encryption key as well as a private key that only the user knows. A user can encrypt a message to a recipient using their public key.  When the user receives the message, they can decrypt it using their private key. To speed up the encryption process, which can be time consuming, PGP leverages a faster encryption algorithm that affects the message. The program then uses the public key to encrypt the now shorter message key. The recipient will receive both the encrypted message and short key. When opening the message, their private key will first decrypt the short key and then the short key will decrypt the message.

Pretty Good Privacy also allows digital signatures. The program’s algorithm creates a mathematical summary (or hash) of the user’s name and signature information. This hash code is then encrypted into the sender’s private key. Recipients can use the sender’s public key to decrypt the hash code. This ensures that the message has arrived securely from the stated sender, thus proving the messages is not spam.