Cryptography Part 1: Origins & Basics 📜

Cryptography Video Summary
History
Begins in 2000 BC with pyramids using hieroglyphics to store data about the life story of a king.
Basic Concepts
The term "Security" and cryptic words like "hvxfitbg" and "xrhnyk" by Sunil are introduced.
Types of ciphers: Substitution, Monoalphabetic, and Polyalphabetic.
Ancient Methods
Hebrew Cryptography: Simple letter substitution.
Spartans: Scytale cipher.
Romans: Caesar cipher shifted by three positions.
Examples
"I need cash" encrypted to "l Q…".
"Sunil is on the go" encrypted using varied shift techniques.
Modern Usage
WW1 and WW2: Cryptography played a crucial role.
16th-century France: Henry V and Blaise developed Polyalphabetic Caesar cipher.
Types of Encryption
Symmetric (Private Key) and Asymmetric (Public Key).
Examples of key lengths: PINs, mobile patterns, and file passwords.
Technical Specs
Bit rates: 128, 256, 512, 1024 bits.
Algorithm and Key: Defined as a set of rules and a sign of code or value for encryption.
Advanced Concepts
Blockchain and Bitcoin: Use cryptographic algorithms.
KeySpaces: Different binary values used for encryption.
Security Features
Confidentiality, Integrity, Authentication, Authorization, and Non-Repudiation are the five pillars of a secure system.
Special Cases
One-time PAD and XOR functions.
Applications
Steganography: Security through obscurity.
Hashing, Ciphering, and Salting techniques.
File Encryption
Example: For symmetric encryption with 8 people, you would generate a separate key for each pair, leading to 28 private keys.
The video concludes by emphasizing the significance of cryptography in securing data and facilitating secure transactions.