DeVry University

CEIS210

Week 2 Lab

Data Standard Encryption (DES): An Exercise in Hand Calculations

Before starting this lab, please make certain to read and understand the document entitled “SIMPLIFIED DES,” which is available via a link in the Week 2 Lesson. It is actually Appendix G in the textbook. This document introduces a simplified approach to the DES encryption/decryption algorithm.The philosophy behind it is to give the student the opportunity to actually do these processes by hand to get the gist of the DES technique. Most of the operations involved in this algorithm are also present in other encryption algorithms. Once you are comfortable with this document and the calculations presented in it, proceed as follows:

1.       Obtain from your professor a unique 10-bit key (unique to each individual student).

2.       Obtain from your professor a unique 8-bit message (unique to each individual student).

3.       Start going through the steps described in the document to encrypt this message.

4.       These individual steps must be documented in full detail. Remember that you are doing this to get the feel and the experience of actually going through a symmetric encryption technique, so thoroughness is important here.

5.       Once you succeed in encrypting the message, go back and decrypt it and verify that your cipher text is indeed resolvable into the original plaintext.

6.       Prepare a detailed lab report documenting all the steps, with captions detailing what each step represents.

7.       Plan on spending a few hours on this educational venture.

10-bit key is: 11000 11110

8-bit message is: 0010 1000