More correctly known as Triple Data EncryptionAlgorithm (TDEA). A block cipher encryption method that uses the DES encryption algorithm to encrypt message blocks three times, using three different 56-bit keys. Triple DES is highly secure, but slow, and largely has been superseded by Advanced Encryption Standard (AES). See also AES, algorithm, block, DES, encryption, and key.
A cipher that, as does DES, operates on 64-bit data blocks. There are several variants, each of which applies the basic DES algorithm three times. Some forms may use two 56-bit keys, whereas others may use three.