Solving the Double Keyword Cipher

Iteration (loops)
1. If the user hasn't inputted a message, then they will outputted with the same question until they do.
2. If the user hasn't inputted a key, then they will outputted with the same question until they do.
Selection (decision)
1. To ask whether the user wishes to encrypt, or decrypt a message.
Lists
1. To be able to list letters of the alphabet.
2. To be able to list the special characters that should be recognisable to my programme (without outputting errors)
To be able to validate the work
1. To ensure the appropriate messages are being inputted (particularly the individual characters).
Modulus
1. So the alphabet may loop together to make encryption and decryption more effective.
Encryption
1. To fulfil the criteria of this task.
2. So the programme knows what function to apply to the message inputted.
Decryption
1. To fulfil the criteria of this task.
2. So the programme knows what function to apply to the message inputted.
Ask for a message/key
1. To fulfil the criteria of this task
Print
1. To output the final result (encrypted message/decrypted message.
Text file
1. I will need a text file to relay information from PyScripter onto a plain white file (for aesthetics).

Resource summary

	Created by Yasmin F over 10 years ago