Glossary

Post-quantum vocabulary, defined.

Cryptographically relevant quantum computer (CRQC)
A future quantum computer powerful and stable enough to break widely deployed public-key cryptography. No such system exists publicly today.
Post-quantum cryptography (PQC)
Cryptographic algorithms designed to resist attacks by both classical and quantum computers, even before any CRQC arrives.
Public key exposure
Whether a wallet's public key has been revealed on-chain. Exposure increases theoretical future quantum risk for some address types.
Harvest now, decrypt later
The risk that attackers collect encrypted data now and decrypt it later when capabilities improve.
Cryptography inventory
A structured record of protocols, certificates, keys, libraries, vendors, backups, and systems that rely on cryptography.
Crypto-agility
The ability to change cryptographic algorithms, libraries, and protocols without redesigning the system.
ML-KEM
NIST-standardized post-quantum key-establishment mechanism (based on Module-Lattice KEM).
ML-DSA
NIST-standardized post-quantum digital signature algorithm (based on Module-Lattice DSA).
SLH-DSA
Stateless hash-based NIST post-quantum signature standard with a different security design than lattice-based signatures.
Hybrid cryptography
Combining a classical algorithm with a post-quantum algorithm so a system stays secure if either holds up.
Cryptographic agility evidence
Documentation that a system can switch algorithms or libraries with predictable engineering effort.
Quantum-aware vs quantum-safe
Quantum-aware describes a project that acknowledges PQ risk; quantum-safe is a stronger claim that requires verifiable evidence and review.