Des — And 3des

Rearranges the 64 bits of the input block.

The inverse of the initial permutation to produce the final ciphertext. 2. Triple DES (3DES) DES and 3DES

Each of the 16 rounds involves expansion, XOR with a subkey, substitution (via S-boxes), and permutation. Rearranges the 64 bits of the input block

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

3DES was introduced to extend the life of DES by applying the algorithm three times to each data block, significantly increasing the effective key length to combat brute-force attacks.