S-DES(simplified Data Encryption Standard)

*Developed in 1996 as a teaching tool
at Santa Clara University
by Prof. Edward Schaefer

*Takes an 8-bit block plaintext, a 10 –bit key and produces an 8-bit block of ciphertext

*Decryption takes the 8-bit block of ciphertext, the same 10-bit key and produces the original 8-bit block of plaintext

Five Functions to Encrypt

IP – an initial permutation

fk - a complex, 2-input function

SW – a simple permutation that swaps the two nybles

fk - a complex, 2-input function; again

IP – inverse permutation of the initial permutation