History — a short PQC timeline¶
Prereqs: Motivation
Next: Problems
Learning goals. Place classical public-key crypto, early PQC ideas, the NIST competition, and today’s standards on one mental timeline — without memorizing every year.
Why a timeline helps¶
PQC is not a brand-new idea that appeared the day NIST finished. Some families (especially code-based McEliece-style crypto) are decades old. What changed is urgency (quantum threat + recorded traffic) and standardization (shared parameters, test vectors, protocol drafts).
Postcard timeline¶
| Era | What mattered | Plain takeaway |
|---|---|---|
| 1970s | Public-key crypto becomes practical (Diffie–Hellman, RSA ideas) | Honest parties can agree on secrets without a prior shared key |
| 1978 | McEliece proposes public-key encryption from error-correcting codes | “Hard decoding” as a crypto puzzle — a PQC ancestor before “PQC” was a buzzword |
| 1990s–2000s | Lattice / LWE-style hardness enters crypto seriously; more code-based and hash-based designs | Alternative public-key families mature in research |
| 1994 / 1996 | Shor / Grover quantum algorithms (theory) | RSA/ECC face a future quantum break; symmetric needs larger margins |
| 2010s | “Store now, decrypt later” becomes a planning slogan; hybrid thinking grows | Migration is a multi-year systems problem, not a weekend patch |
| 2016–2024 | NIST Post-Quantum Cryptography project: call → rounds → selections | Community stress-tests candidates in public |
| 2024 onward | Standards such as ML-KEM, ML-DSA, SLH-DSA; more KEMs (e.g. code-based paths) continue | Deployers get concrete algorithms; research does not stop |
Dates above are orientation slogans, not a legal chronology. When a paper cites a year, trust that paper’s bibliography.
Four families you will meet (names only)¶
You do not need definitions yet — only the postcard:
| Family | Hardness slogan (later pages unpack) | Flavor |
|---|---|---|
| Lattice / LWE | Noisy linear equations stay hard | Basis of ML-KEM / ML-DSA-style designs |
| Code-based | Decoding a random-looking linear code is hard | McEliece / QC-MDPC / HQC-shaped ideas |
| Hash-based | Hash preimages / few-time signatures | SLH-DSA (SPHINCS+) style |
| Others | Multivariate, isogeny-adjacent, … | Important in research; fewer “default deploy” slots today |
This curriculum spends the most time on codes and lattices, plus a hardware track for how chips implement the arithmetic.
Standardization vs research¶
| Body / world | Role |
|---|---|
| NIST | Selects / standardizes algorithms many products will ship |
| IETF / TLS world | Puts algorithms into protocols |
| IACR + ePrint | Theory, cryptanalysis, new schemes |
| IEEE / CHES-style HW | Accelerators, SCA, systems engineering |
Standards freeze a snapshot. Research keeps attacking, improving, and measuring. Both matter: standards for deployers; papers for understanding why parameters look the way they do.
Quick self-check¶
Was code-based public-key crypto invented after NIST’s PQC project?
Answer
No — McEliece (1978) is much earlier. NIST popularized and stress-tested modern parameter sets and families; it did not invent the idea of “codes as crypto.”Next¶
Problems — what “easy forward, hard backward” means before any matrices.