Encryption is a widely used technique which involves making information indecipherable to protect it from unauthorised viewing or use, especially during transmission or when it is held on removable magnetic media. Encryption is usually based on a key(s) without which the information cannot be decoded (decrypted). The most widely used encryption system is DES (Data Encryption Standard) although increasingly this is being replaced commercially by the more secure public key system RSA. Message Authentication Message authentication makes use of encryption to create a digital signature which is appended to a transaction. This does not scramble the data but any difference in the digital signature at the receiving end will indicate some form.
