DES Encryption

The Data Encryption Standard (DES) encryption functions use a 56-bit key to encrypt data. If two credential users (or principals) know the same DES key, they can communicate in private, using the key to encipher and decipher text. DES is a relatively fast encryption mechanism. A DES chip makes the encryption even faster; but if the chip is not present, a software implementation is substituted.

The risk of using just the DES key is that an intruder can collect enough cipher-text messages encrypted with the same key to be able to discover the key and decipher the messages. For this reason, security systems such as Secure NFS change the keys frequently.