Cryptography and network security

Homework final

1.

Question: Write a program in MATLAB or C/C++ that can encrypt and decrypt using S-DES (simplified DES).

Test data: Use plaintext, ciphertext and the key of problem 3.18. Put comments on your program script and send me a zip file with all of the program files and your results (output screen capture) pages, with your name as the file name.

3.18 Using S-DES, decrypt the string (10100010) using the key (0111111101) by hand.

Show intermediate results after each function (IP, Fk, SW, Fk, IP-1). Then decode the

first 4 bits of the plaintext string to a letter and the second 4 bits to another letter

where we encode A through P in base 2 (i.e., A = 0000, B = 0001,..., P = 1111).

2. 

Modify your S-DES program which you created last week to work in triple-S-DES mode. Submit your software and print out of your output screen.

3.

Please follow the link below to start your AES lab assignment. The lab report is due by Sunday. 

http://williamstallings.com/Crypto/AESCalc/AESlab.html