56-bit effective key length (plus 8 parity bits for a total of 64 bits). Block Size: 64 bits. Process Steps:
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.
Developed in the 1970s, DES was the global standard for decades before its 56-bit key became vulnerable to modern brute-force attacks.
