Due: May 22, 2010 (before class)

Hand in: Hard copy

Weight: 10 points

This goal of this assignment is to understand the practical use and application of popular private key algorithms, specifically, SHA, MD5, and 3DES.  Below is a flowchart of encrypting a file with a password.  The outcome is a file with two parts a ciphered data and a header with a hashed password.

Answer the followings:

1. What is the role of the following boxes shown in the flowchart: SHA Hash, MD5 Hash, and 3DES Encypter in the context of what we are trying to accomplish?

2. Is the box for MD5 Hash necessary? Explain.  What will happen if we remove it?