Data Encryption Standard
The Data Encryption Standard (DES) algorithm uses a key to encrypt/decipher a 64 bit block data. It first divide the data in to 64 bit data and then adds the key to every 64 bit block while encription/deciphering. At the receivers end it asks for key to decript/cipher it.
DES has been replaced by Advanced Encryption Standard (AES) (Advanced Encryption Standard) as the National Security Agency's official "secure encryption" algorithm.