Question: How a piece of a plaintext can be compromised in data communication?

Question: How the historical algorithms (ceasar cipher, simple substitution cipher, atbash cipher, vigenere cipher and playfair cipher) used to work and why they are not working right now? What were their disadvantages? Describe the other two more complicated algorithms which are Simple One-Time Pad and Vernam cipher and their properties (Cover Time, Complexity, Key management issues with OTP).

Course: Cryptography