WRITE YOUR NAME HERE:_____________________________________

• Date: Wed, Oct 17 , 11:00 AM - 11:50 AM in class
• Quiz 2 consists of 4 questions. Each Question 25 points

You have to EXPLAIN your answer in detail.

Problem 1: (25 points)
Using the KEY MATRIX A

3	8
7	11

Encrypt: monday

Problem 2 (25 points)
Decrypt the message: KGYXSH, which was encrypted using the key matrix A

3	8
7	11

Problem 3 (25 points)

• PART I (15 points)
  Find an inverse of matrix A

  5	11
  7	8

• PART II (10 points)
  Decrypt the message JLJI that was encrypted by Vigenere cipher first, with the key DOG and after that by Hill Cipher with the key matrix A

  5	11
  7	8

Problem 4 (25 points):
Encrypt: HEBREW using Vigenere Cipher with key GUY and then encrypt the obtained ciphertext using Hill Cipher and the matrix from Problem 1.

Helpful Links

• Multiplicative Inverse Applet - written by Andrew Burns
  • Wolfram|Alpha: Computational Knowledge Engine
  • Hill Cipher Applet by Dr. Ahmed Desoky
    GOOD LUCK!