Review Questions

Complete Chapter 4 Review Questions 4.4, 4.6, and 4.7 in short answer format.

Complete Chapter 7 Review Questions 7.3, and 7.4 in short answer format.

 Solve problem 4.6   and solve problem 4.7   of the textbook. Show all required work and include a short paragraph that provides your reasoning for how you arrived at your answer. Also include a paragraph about how the content of these problems can be used in a real-life situation.

1. 4.4 What is a product cipher?

2. 4.6 Which parameters and design choices determine the actual algorithm of a Feistel cipher

3. 4.7 Explain the avalanche effect

4. 7.3 The MerkleHellman attack on 3DES begins by assuming a value of A=0  

5. 7.1b ). Then, for each of the 256 possible values of K1, the plaintext P that produces A=0 is determined. Describe the rest of the algorithm  7.4 With the ECB mode, if there is an error in a block of the transmitted ciphertext, only the corresponding plaintext block is affected. However, in the CBC mode, this error propagates. For example, an error in the transmitted C1 (

6. 1. Figure 7.4) obviously corrupts P1 and P2.

      1. Are any blocks beyond P2 affected?

      2. Suppose that there is a bit error in the source version of P1. Through how many ciphertext blocks is this error propagated? What is the effect at the receiver?