Quantum Cryptography vs Post-Quantum Cryptography

What is the difference between quantum cryptography and PQC?

Quantum cryptography uses quantum physical effects; post-quantum cryptography uses mathematical algorithms intended to resist quantum attacks. Quantum key distribution, or QKD, establishes key material through a suitable physical link. PQC includes software key-encapsulation and signature schemes that run on conventional computers. The right comparison is the protected operation, equipment and trust model, rather than which label sounds more advanced.

Source-derived comparison. Джерела: NIST — quantum cryptography · NIST FIPS 203 — ML-KEM · NIST FIPS 205 — SLH-DSA.

The comparison uses NIST’s quantum-cryptography explanation і PQC definition. Specialized equipment matters to the deployment model, but hardware or software alone does not establish the security of endpoints, applications or the complete network.

Use the claim classifier to check how a product claim distinguishes QKD, key encapsulation and signatures from its equipment, inputs and outputs.

Why does quantum key distribution still need authentication?

Quantum key distribution still needs authenticated communication: exchanging key material does not, by itself, prove the identity of the other endpoint. NIST’s quantum-network integration work describes authentication of QKD messages on the classical channel. Security therefore depends on the complete protocol and its endpoint assumptions, rather than on the presence of a quantum link alone.

Source-derived comparison. Джерела: NIST — authenticated messages in QKD integration.

NIST’s integration account distinguishes key establishment from protection of the protocol messages. Keep authentication and endpoint assumptions attached when citing a QKD security claim.

For wallets, map the parties, authentication keys and consequences of endpoint compromise. A protected link cannot repair software that signs an attacker’s transaction or exposes the private signing key.

Why does QKD not replace a blockchain’s transaction signatures?

A public blockchain needs independent nodes to verify transaction authorization without sharing each wallet’s private secret. Digital signatures provide that public-verification function. QKD distributes key material between communication parties and is not, by itself, the same authorization mechanism. Adding a quantum link between selected servers therefore does not automatically replace the spending keys or verification rules used by every wallet.

Editorial synthesis. Source context: NIST FIPS 204 — ML-DSA · NIST — quantum cryptography.

NIST stateful-signature recommendation describes a signature’s public-key verification role. Our definition connecting quantum cryptocurrency to actual spending rules applies this distinction to coin terminology.

Use the wallet map separating key establishment from transaction signing to inventory a real transfer. Evaluate the message signature, transport and recovery path independently before combining them into a network-wide claim.

Why public-ledger records do not need future decryption.

Which post-quantum standards matter to a software wallet?

The relevant standard depends on the operation: ML-KEM addresses key encapsulation, while ML-DSA and SLH-DSA address digital signatures. SynergyX specifies Kyber-768 and SPHINCS+-SHAKE-128s for those separate software roles; users do not need a quantum communication link for that design. Matching a release to finalized standards and checking its signing, verification and recovery behavior remain separate implementation tasks.

The PQC standards table mapping each algorithm to its function links the exact NIST publications. Earlier algorithm-family names should not be silently substituted for finalized standard names.

We compared each approach by protected operation, hardware, authentication and public verification. We did not test QKD equipment or benchmark wallet binaries. Apply the security checklist linking wallet claims to release evidence when reviewing an implementation.