A
widely used method of private-key data encryption that originated
at IBM® in 1977 and was adopted
by the U.S. Department of Defense. DES supports 72 quadrillion or
more possible encryption keys; for each message, the key is chosen
at random from among this enormous number of possible keys. Like all
other private-key cryptographic methods, both the sender and the receiver
must know and use the same private key.
DES applies a 56-bit key
to each 64-bit block of data. Although this is considered strong encryption,
many companies use triple DES, which applies three keys in succession.