PQC 101: Introduction
Understand the quantum threat, explore NIST PQC standards, and compare classical vs post-quantum cryptography.
PQC 101 — The Quantum Threat & What To Do About It
A beginner-friendly introduction to Post-Quantum Cryptography in 5 steps.
Why PQC?
The Quantum Threat
Today's most widely used encryption — and — relies on math problems that are extremely hard for classical computers. But quantum computers using an algorithm called can solve these problems exponentially faster.
What's at risk?
- Online banking & payments — TLS connections use RSA/ECC
- Government & military secrets — classified data encrypted with RSA
- Medical records & personal data — long-lived data at risk from “Harvest Now, Decrypt Later”
- Digital signatures & code signing — firmware and software updates (HNFL risk)
Key concept: HNDL
“” (HNDL) is an attack strategy where adversaries collect encrypted data today and store it until quantum computers can break the encryption.
This means data encrypted now with RSA or ECC could be readable in the future. For sensitive data with long lifespans (health records, state secrets), migration must start before quantum computers arrive.
Key concept: HNFL
“” (HNFL) is the signature counterpart to HNDL. Adversaries capture signed artifacts today — firmware images, certificate chains, code-signing blobs — and store them. Once a quantum computer exists, they can forge or repudiate those signatures retroactively.
Unlike HNDL (which targets confidentiality), HNFL targets authenticity and integrity. Long-lived credentials — PKI hierarchies, firmware signing keys, code-signing certificates — must migrate to PQC signing algorithms (, ) before quantum computers mature.
Use the Next → button below to continue.