In a nutshell, DES (Data Encryption Standard) is an algorithm published by the National Institute of Standards for data encryption. 3DES (triple DES) is the DES algorithm applied three times to a data stream. The longer explanation of the standard is a bit more complicated.

DES was developed by IBM in 1977 and was adopted by the U.S. Department of Defense. It includes the algorithm in the FIPS (Federal Information Processing Standard) 46 publication.

DES uses a key system for encryption, and both the sender and receiver of a message encrypted with DES must have the same private key - data in transit cannot be deciphered without the appropriate key. Keys are chosen at random, and there are 72,000,000,000,000,000 (that's 72 quadrillion) possible keys. The algorithm involves 16 operations in which the 56-bit key is assigned to a 64-bit block of data.

DES is a symmetric block cipher encryption method. It is considered symmetric because the same private key is used for encryption and decryption. (This is in contrast to asymmetric encryption, which uses a private key and a readily available public key) A "cipher" is simply a method of encryption and decryption, and the "block" refers to the fact that blocks of data (64-bits) are encrypted at the same time, i.e., DES does not encrypt each individual bit of data.

DES encryption is strong enough to keep most hackers at bay, but its code is breakable. Many have begun using 3DES as a stronger alternative. 3DES performs the DES encryption process three times using three different keys. The security provided by 3DES is very strong, but the technology is slower than some of the encryption standards that have recently emerged.