There are two inputs to the encryption function: plaintext to be encrypted (64 bits) and the key (56 bits).
The left side shows the basic process for enciphering a 64-bit data block which consists of three phases:
An Initial Permutation (IP) which shuffles (rearranges) the 64-bit input plaintext to produce the permuted input.
16 rounds of a complex key dependent round function, involving substitutions & permutations. The output of the 16th round consists of 64 bits that are a function of the input plaintext and the key. The left and right halves of the output are swapped to produce the pre output.
A Final Permutation, being the inverse of IP of the preoutput produce the 64 bit ciphertext.
Editor: Neha Bhosale Added on: 2020-05-05 20:17:37 Total View:377