Intro to Cryptography WGU C839|62 Questions with 100% Correct Answers | Updated & Verified

The same key is used to encrypt messages as well as decrypt messages. These algorithms are always faster but have an issue with exchanging keys. - ️️Symmetric Cryptography Modern cryptography began when Claude Shannon publish "Communication Theory of Secrecy Systems" in 1949. He focused on this concept by quantifying information, leading to a number of methods for encrypting and decrypting information. - ️️Information Theory Change to one character in plain text affect multiple characters in the cipher text. - ️️Diffusion Attempts to make the relationship between statistical frequencies of the cipher text and the actual key as complex as possible. Uses complex substitution algorithms. - ️️Confusion A small change yields large effects in the output. Fiestel's variation on Claude Shannon's concept of diffusion. Ideally, a change in one bit of plaintext would change all the bits in the ciphertext. - ️️Avalanche A cryptosystem should be secure even if everything about the system, except the key, is publicly known. - ️️Kerckhoffs's Principle C = E(k,p) expresses what mathematically? - ️️Symmetric Algorithm for Encryption P = D(k,c) expresses what mathematically? - ️️Symmetric Algorithm for Decryption