Definition: A "key" is a numerical or other value associated with an encryption program that renders information to be unreadable and then switched back to become readable again. The secret that is needed to protect the message is typically shared between the sender and receiver. The sender can use the special code to scramble the content of the message. The receiver, using the shared secret, can unlock the secret message.
Its Relevance: The encryption programs that control the re-arrangement and translation of messages are indispensable for business to business or business to customer transactions. Information such as credit card numbers can be securely sent on-line without fear of disclosure. Encryption management is essential to information assurance. The security policies of an organization or business must address what encryption should be used and under what circumstances.