Part II — Primitives
The black boxes: the ciphers, the hashes, the signatures. Treated as parts with a well-defined security property — what you combine, not what you invent.
| # | Section | What it covers |
|---|---|---|
| 1 | Symmetric primitives | Block × stream, SPN/Feistel, AES, modes of operation, AEAD, and nonce discipline. |
| 2 | Hash, MAC, and KDF | Hash properties, SHA-23BLAKE, HMAC, HKDF, and password hashing (Argon2id). |
| 3 | Asymmetric primitives | Trapdoor functions, DHECDH, RSA, curves (X25519Ed25519), KEM × signature, hybrid model. |
Previous part: I — Fundamentals. Next: III — Protocols — how the primitives are choreographed in TLS, Signal, and PKI.
For dense reference, see Part VIII — Reference.