Cryptography

How secrets are kept — the theory and the working practice behind modern crypto.

Books

• A Graduate Course in Applied Cryptography (Book) — Dan Boneh and Victor Shoup’s free graduate textbook, from secret- and public-key basics to elliptic curves, post-quantum lattices, and secure multi-party computation.
• The Joy of Cryptography (Book) — Mike Rosulek’s free, open-access MIT Press undergraduate textbook on provable security, from the one-time pad through pseudorandom functions, RSA, and zero-knowledge proofs. Starred sections mark the genuinely optional detours — Secret Sharing, Universal Hash Functions — so the core path stays lean.

Explainers

• A Stick Figure Guide to the Advanced Encryption Standard (AES) (Article) — Moserware’s “play in 4 acts”: the fall of DES, then confusion and diffusion, then the state matrix through SubBytes / ShiftRows / MixColumns / AddRoundKey, then the finite-field algebra underneath — with a “Foot-Shooting Prevention Agreement” to sign before you go implementing it.

Videos

• The Insane Real Engineering of the Nazi Enigma Machine (Video) — Veritasium’s 47-minute history, filmed with the experts at Bletchley Park and the National Museum of Computing: how the rotors worked, the Polish codebreakers who broke Enigma first, the operator habits that Turing’s Bombe exploited, and the harder Naval Enigma. It closes by handing viewers a Naval Enigma message that has never been broken.