The inverse of the initial permutation to produce the final ciphertext. 2. Triple DES (3DES)
Rearranges the 64 bits of the input block. DES and 3DES
Each of the 16 rounds involves expansion, XOR with a subkey, substitution (via S-boxes), and permutation. The inverse of the initial permutation to produce
56-bit effective key length (plus 8 parity bits for a total of 64 bits). Block Size: 64 bits. Process Steps: XOR with a subkey