Needed 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 are required to implement mechanisms for Bob's 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.