Project 4.1
Project 4.2
Project 4.3
Project 4.4
Project 4.5
Project 4.6
Reference:
Project 4.7
Project 4.8
Project 4.9
References:
Project 4.10
References:
Project 4.11
Project 4.12
Project 4.13
Project 4.14

Project 4.15
Reference:
Project 4.16
References:
Project 4.17
References:
RSA Data Security Secret-Key Challenge:
http://www.rsasecurity.com/
Note: If you look at the page Status and Prizes, you will see the contest RC5-32/12/5 This $10,000 prize was won by deciphering the following secret message: "Strong cryptography makes the world a better place."