PGP, or Pretty Good Privacy, is the most recognized public key encryption program on earth. PGP is used in many applications in order to protect people's privacy. It is used in emails, data files, drives and also instant messaging.
The internet can be vulnerable to spying from unscrupulous parties. Data packets can be intercepted, while mail servers can store messages indefinitely, which can be accessed and read at any point in time by someone who can access it. With email not protected by law as a private communication (unlike phone calls or letter), it can be read by any third party or group without any express permission of the author.
PGP gives the privacy that is needed for safe transmission of online communication. What PGP does is to change plain text into a complicated code comprised of characters that are unreadable to anyone. This encrypted form of the message travels to its destination. The recipient will then use PGP to decrypt the message and return it to its readable form.
The simple method used behind this widely used public key encryption is the utilization of customized key pairs. These key pairs consist both of a public key and a private key. The public key is used in encrypting messages. The private key, on the other hand, is used in decrypting it.
In order to send an encrypted message to a person that uses PGP, the sender only need the recipient's public key. Each public key is considered unique and will only work with the private key in the key pair. If the sender uses a different public key and sends it to the recipient, the recipient will not be able to decrypt the message.