Differential Cryptanalysis Fundamentals
Learn input-output difference propagation to attack reduced-round ciphers.
What Is Differential Cryptanalysis?
Differential cryptanalysis (Biham & Shamir, 1990) is a chosen-plaintext attack that analyzes how differences in plaintext pairs propagate through a cipher. By finding input differences that produce predictable output differences with high probability, an attacker recovers key bits statistically.
Difference Definition
For XOR-based ciphers: difference ΔX = X XOR X'. For addition-based ciphers: difference ΔX = X - X' mod 2^n. XOR differences are most common since XOR commutes with XOR-keying (key schedule effects cancel in differential pairs).
All lessons in this course
- Differential Cryptanalysis Fundamentals
- Linear Cryptanalysis & Approximation Tables
- Birthday & Collision Attacks
- Meet-in-the-Middle & Time-Memory Trade-offs