encryption

The process of encoding information in an attempt to make it secure from unauthorized access, particularly during transmission. The reverse of this process is known as decryption.

Two main encryption schemes are in common use:

• Private (Symmetrical) Key An encryption algorithm based on a private encryption key known to both the sender and the recipient of the information. The encrypted message is unreadable and can be transmitted over nonsecure systems.
• Public (Asymmetrical) Key An encryption scheme based on using the two halves of a long bit sequence as encryption keys. Either half of the bit sequence can be used to encrypt the data, but the other half is required to decrypt the data.

See also Data Encryption Standard; Pretty Good Privacy; ROT-13.