What is DES?
DES (“Digital Encryption Standard”) is an open encryption standard that offers weak encryption at 56-bit strength. DES used to be considered strong encryption, but the world’s fastest computers can now break DES in near real time. A cryptographically valid improvement on DES is 3DES (“Triple DES”) – a strong encryption standard that is still in use.
DES was one of the first open encryption standards designed for widespread use in computing environments, and it was submitted by IBM in 1975 based on previous work on an algorithm called Lucifer. It was also the first encryption algorithm to be specified by a “FIPS publication”: FIPS 46 (and subsequent FIPS 46-1, 46-2 and 46-3 revisions).
See the Wikipedia entry for DES if you are interested in the technical mechanics behind DES.