Cryptography Part 2: Symmetric Encryption
Channel: Tom Olzak
Date: 2021-08-05

Today’s approaches to the cryptographic protection of information include symmetric and asymmetric encryption.  In this lesson, I describe cryptographic entropy, how symmetric encryption achieves it, and the reason why it is not practical to crack AES encryption.

Table of Contents:
00:00 - Intro
00:30 - Cryptographic Entropy
02:40 - Stream Ciphers
06:10 - Block Ciphers
08:03 - Substitution Box (S-Box)
08:49 - Permutation Box (P-Box)
09:18 - Electronic Code Book (ECB)
09:50 - Cipher Block Chaining (CBC)
10:29 - Cipher Feedback Mode (CFB)
11:21 - Counter Cipher Mode (CTR)
11:56 - Kerkhoff's Principle
12:35 - When to use Symmetric Encryption