Question 1 Implement Mechanism 1 and 2. Ensure that you show your implementation for all parts, including how Bob authenticates the message sent to him from Alice. 1. She generates a 2048-bit private and public key. [4 marks]

2. Alice and Bob negotiate a shared key (Ks) using Diffie-Hellman protocol with p = 23 and g =17. [10 marks]

3. Alice performs steps 4 to 9.

4. Alice hashes the message: To prevent the spread of germs, you should wash your hands with soap and water for at least 20 seconds or use a hand sanitizer with at least 60% alcohol to clean hands. [3 marks]

5. She encrypts the hash using her private key to produce a message digest. [2 marks]

6. Her public key is encrypted using the DES/AES algorithm. The secret DES/AES key (Ks) used is from step 2. [3 marks]

7. The encrypted private key is saved to a file called privatekey.dat while the public key to publickey.dat. [2 marks]

8. The private key is used to encrypt the hash of the message with RSA. [3 marks]

9. Alice then sends the message, message digest and encrypted public key to Bob over a public communication channel. [1mark]

10. Bob receives the message, message digest and encrypted public key. [1mark]

11. Bob decrypts the encrypted public key to recover the Alice's public key. [2 marks]

You are required to implement mechanisms that achieves the goals of Mechanism 1 and 2. [9 marks]

Sub-total [40 marks]

Submit:

1. The program that runs on Alices machine: Alice.py

2. The program that runs on Bobs machine: Bob.py

3. The message displayed (take a screenshot) from Bob indicating whether the was authenticated, and integrity verified: AuthInteg.jpg

The purpose of this assignment is to understand which cryptographic functions can be used to accomplish a certain security objective. In this exercise Alice will send a short message to Bob. The message would be sent to Bob along with an encrypted message digest. Bob is required to authenticate and verify the integrity of the message sent. Assumptions: 1. A client-server architecture is used for communication by Alice and Bob. 2. An attacker is on the data path that data passes. 3. An attacker can do the following: i. Eavesdrop on messages, i.e. listen to the transmission ii. Modify messages iii. Impersonation attacks. You were required to implement mechanisms for Bob security services. Message integrity - Mechanism 1 Authenticity of the sender - Mechanism 2. To do this you decide to utilize Python Libraries. All implementations should be done in Python. . The purpose of this assignment is to understand which cryptographic functions can be used to accomplish a certain security objective. In this exercise Alice will send a short message to Bob. The message would be sent to Bob along with an encrypted message digest. Bob is required to authenticate and verify the integrity of the message sent. Assumptions: 1. A client-server architecture is used for communication by Alice and Bob. 2. An attacker is on the data path that data passes. 3. An attacker can do the following: i. Eavesdrop on messages, i.e. listen to the transmission ii. Modify messages iii. Impersonation attacks. You were required to implement mechanisms for Bob security services. Message integrity - Mechanism 1 Authenticity of the sender - Mechanism 2. To do this you decide to utilize Python Libraries. All implementations should be done in Python