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Foundations

Quantum cryptography foundations: from Shor's to PQC

Whether you are a CISO, security engineer, or curious developer, this guide sequences the best explainers and NIST references into a coherent learning path. Each layer links to video companions on our blog (with embedded YouTube players) and open-source PQC libraries in the Learn catalog.

Quantum cryptography foundations: from Shor's to PQC illustration

Superposition

Compare feasible plans before you collapse to one.

Phase

Feasibility first, then rank against the operational objective.

Measurement

Ranked plan, short why, and the metric behind the call.

Open the full curriculum hub for the video companion grid, diagram gallery, and layer checkpoints — or continue with the narrative guide below.

Layer 1 — Why quantum breaks RSA and ECC

Watch: /blog/video-companion-shors-algorithm-minutephysics and /blog/video-companion-quantum-power-veritasium. Read: /blog/shors-algorithm-explained-for-cisos and NIST's PQC overview at nist.gov/pqc.

Checkpoint: Can you explain why Shor's breaks RSA but AES-256 mostly survives?

Layer 2 — Harvest now, decrypt later

Watch: /blog/video-companion-hndl-jeremy-allison and /blog/video-companion-mosca-intel-quantum-security. Read: /blog/mosca-inequality-worked-examples and the HNDL hub at /q-day/hndl.

Checkpoint: Apply X + Y > Z to one data class with the Mosca calculator.

Layer 3 — NIST PQC standards

Watch: /blog/video-companion-pq-algorithms-nist and /blog/video-companion-kyber-dilithium-menezes. Read: /blog/nist-fips-203-204-205-primer and /q-day/frameworks/ml-kem.

Checkpoint: Name ML-KEM, ML-DSA, and SLH-DSA and what each replaces.

Layer 4 — Migration in practice

Watch: /blog/video-companion-dustin-moody-nist-strategy and /blog/video-companion-cisa-quantum-readiness. Read: /blog/hybrid-tls-migration-guide and /blog/pqc-migration-phases-explained.

Checkpoint: Describe hybrid TLS and list three non-HTTPS crypto locations.

Layer 5 — Crypto agility and evidence

Read: /blog/crypto-attack-surface-map, /blog/qkd-vs-post-quantum-cryptography, and /blog/reading-qtangl-cbom-export. Download: /downloads/quantum-crypto-learning-guide.md.

Checkpoint: Explain what a CBOM is and why re-scan proof matters.

Resources to open next

The goal of this guide is to help you navigate toward the right tools, not stop at the overview. The resources below are the strongest next clicks for this topic.

liboqs illustration
open-quantum-safePost-quantum cryptography

liboqs

C library for prototyping and experimenting with quantum-resistant cryptography

CMITFlagship

2,946 stars · Updated 3mo ago

openssl illustration
open-quantum-safePost-quantum cryptography

openssl

[DEPRECATED — See notice in README.md and switch to OpenSSL 3 OQS Provider] Fork of OpenSSL 1.1.1 that includes prototype quantum-resistant algorithms and ciphersuites based on liboqs

CBSD-3-ClauseArchive

307 stars · Updated 8mo ago

PQClean illustration
PQCleanPost-quantum cryptography

PQClean

Clean, portable, tested implementations of post-quantum cryptography

C

923 stars · Updated 3mo ago

Next step

Open learning hub.