Consider a simple chatting system wherein each message has to be encrypted using rail fence cipher. During the session establishment, one of the communicating parties sends a key to the other side (which represents the number of lines in which the plaintext has to be aligned when the rail fence algorithm is applied). Then, each sent massage has to be encrypted using the cipher and then decrypted in the other side. In this assignment, you are required to do the following tasks: 1. Build a simple chatting system between two communicating parties on a local machine. (You can use some other code in this task, however, make sure to understand it well as well as citing it in your code comments). The following websites might be helpful for you: 2. Exchange the key between both communicating parties. 3. Encrypt each transmitted message using rail fence cipher. 4. Decrypt each received message using rail fence cipher. 5. Compute the encryption time to send each message and record it alongwide with the size of the message. 6. Plot the message size versus the encryption time for a number of messages.