Data Encryption Standard An encryption algorithm that uses a 56-bit key and maps a 64-bit input block to a 64-bit output block. The key appears to be a 64-bit key, but one bit in each of the eight bytes is used for odd parity, resulting in 56 bits of usable key(Data Encryption Standard); DES(An encryption algorithm that uses a 56-bit key and maps a 64-bit input block to a 64-bit output block. The key appears to be a 64-bit key, but one bit in each of the eight bytes is used for odd parity, resulting in 56 bits of usable key)
