Six pillars
Everything you need to understand PQC
From first principles on quantum physics to a practical migration checklist — each section is self-contained but builds on the previous one.
Quantum Computing Primer
Qubits, superposition, entanglement, hardware approaches, and what "cryptographically relevant" actually means for the threat timeline.
The Cryptographic Threat
Shor's algorithm breaks RSA and ECC. Grover's weakens symmetric keys. Harvest Now Decrypt Later means the attack starts today.
PQC Algorithms & NIST Standards
FIPS 203 (ML-KEM), FIPS 204 (ML-DSA), FIPS 205 (SLH-DSA). Lattice, hash-based, and code-based families explained. IETF, BSI, and Chinese standards too.
Migration Playbook
A five-phase framework: from cryptographic inventory (CBOM) through hybrid rollout to full PQC. Protocol-level guidance for TLS, SSH, VPN, and code signing.
Curated Resources
Annotated links to NIST FIPS documents, IETF drafts, BSI recommendations, CSTC standards, Cloudflare/Google/IBM blogs, and PKI Consortium forums.
Need Expert Guidance?
Qifei Li offers cryptographic architecture review, PQC migration roadmaps, and technical due diligence for tech teams and investors.
Why act now
The clock is already running
Harvest Now, Decrypt Later
Nation-state adversaries are recording TLS-encrypted traffic today. When a cryptographically relevant quantum computer arrives, they will decrypt it retroactively. Classified data from 2025 will be readable in 2035.
Mosca's Inequality: X + Y > Z
X = how long your data needs to remain secret ·
Y = how long your migration will take ·
Z = time until a CRQC arrives.
If X + Y > Z, you are already at risk.
Enterprise migrations routinely take 5–10 years.
Standards are ready
NIST finalized FIPS 203, 204, and 205 on August 13, 2024. Chrome already deploys ML-KEM hybrid key exchange. Cloudflare, AWS, and Signal have shipped PQC in production. The tooling is available; migration can start now.
Quick reference
What breaks, what survives
A quick orientation before diving into the details.
| Algorithm / Protocol | Type | Classical security | Post-quantum status |
|---|---|---|---|
| RSA-2048 / RSA-4096 | Asymmetric KEM / Sig | 112 / 140 bit | ✗ Broken by Shor's |
| ECDH / ECDSA (P-256) | Asymmetric KEM / Sig | 128 bit | ✗ Broken by Shor's |
| DH-2048 / DH-4096 | Asymmetric KEM | 112 / 140 bit | ✗ Broken by Shor's |
| AES-128 | Symmetric cipher | 128 bit | ⚠ Grover → ~64 bit effective |
| AES-256 | Symmetric cipher | 256 bit | ✓ Safe (128-bit PQ security) |
| SHA-256 | Hash function | 256 bit preimage | ⚠ Grover → ~128 bit; prefer SHA-384+ |
| SHA-384 / SHA-512 / SHA3-384 | Hash function | 384 / 512 bit | ✓ Safe |
| ML-KEM (FIPS 203) | PQC KEM | — | ✓ NIST standardized 2024 |
| ML-DSA (FIPS 204) | PQC Signature | — | ✓ NIST standardized 2024 |
| SLH-DSA (FIPS 205) | PQC Signature | — | ✓ NIST standardized 2024 |
Ready to start your migration?
Qifei Li provides cryptographic architecture reviews, PQC readiness assessments, and migration roadmaps for engineering teams.