Part III — Protocols
Where primitives become systems. Choreography between parties over time: who talks to whom, in what order, what to prove — and against which trust model.
| # | Section | What it covers |
|---|---|---|
| 1 | Trust and PKI | The trust problem, forward secrecy, certificates, CA chains, revocation. |
| 2 | TLS: everything together | The TLS 1.3 handshake piece by piece — ECDHE + HKDF + signature + PKI + AEAD; SSH, WireGuard, QUIC. |
| 3 | End-to-end messaging (Signal) | E2EE, X3DH, Double Ratchet, forward secrecy + post-compromise security, plausible deniability. |
Previous part: II — Primitives. Next: IV — Post-quantum — what changes when the quantum computer arrives.
For dense reference, see Part VIII — Reference.