In python, how do you write a program dealing with cryptography that satisfies the following:

Description: 1. Show how to do a rot-13 for the message: "Security is often important" 2. Show how to do a simple (letter by letter) substitution cipher, please encrypt the Mark Twain story. (You will need to create a key, you can do this by hand or use a simple software implementation.) 3. One problem with #2, is that letter frequencies may make cracking easy. For the original (plaintext) show the letter frequencies. 4. One possible solution to #3 is to use homophonic substitution. Show how that can be done. 5. How would you use part 3 (above) to crack a cipher