Claude Shannon is regarded as the father of modern cryptography. His groundbreaking work during World War II laid the foundation for much of the cryptographic theory used today, including concepts like entropy, confusion, and diffusion in encryption algorithms.
The Enigma machine was used by the German military to encode and decode messages during World War II. The machine used a series of rotating wheels to create complex encryption, which was thought to be unbreakable at the time. Allied cryptographers, including Alan Turing, famously broke the code, which played a crucial role in the war.
The Caesar cipher is a classic example of a substitution cipher, where each letter in the plaintext is shifted a certain number of places down the alphabet. For example, a shift of 3 would turn "A" into "D," "B" into "E," etc.
In RSA encryption, the public key consists of two numbers: the exponent (often denoted as "e") and the modulus (often denoted as "n"). These are used by anyone who wants to encrypt a message that can later be decrypted by the recipient using their private key.
The scytale cipher was used by the ancient Greeks, particularly in military contexts. It involved wrapping a strip of parchment around a rod and writing a message along the rod's length. When unwrapped, the message appeared as a jumbled series of letters, which could only be read by wrapping the parchment around a rod of the same diameter.
