Questions
17.1. What are the two major requirements for a useful cryptosystem? (See Section17.1.2.)
17.2. Shannon suggested two encryption concepts that he termed confusion and diffusion. Explain what these terms mean. (See Section 17.3.1.)
17.3. If high-level security is desired, explain why a linear feedback shift register (LFSR) would not be used. (See Section 17.4.2.)
17.4. Explain the major difference between conventional cryptosystems and public key cryptosystems. (See Section 17.5.)
17.5. Describe the steps used for message encryption employed by the Data Encryption Standard (DES). How different is the operation when using Triple-DES? (See Sections 17.3.5 and 17.6.1.1)
17.6. Describe the steps used for message encryption employed by version 2.6 of the Pretty Good Privacy (PGP) technique. (See Section 17.6.1.3.)