tech · quantum risk

Is DoH / DoT Quantum Proof? Network Security & PQC

Risk: medium · Confidence: high · Reviewed: 2026-07-19

Verdict

DoH and DoT encrypt DNS to a resolver using TLS—they are not quantum-proof while that TLS uses classical key exchange and certificates. They also do not replace DNSSEC authenticity.

Overview

DNS-over-HTTPS and DNS-over-TLS protect DNS queries in transit to a resolver. Privacy improves; quantum risk follows the TLS stack.

DNSSEC authenticity is a separate layer (signatures on zone data). See /is-quantum-proof/dnssec. This page focuses on encrypted DNS transport.

Cryptographic profile

Signatures: TLS certificates on resolvers (RSA/ECDSA common)
Hash: TLS and DNS message hashing
Public-key exposure: Resolver endpoints present classical TLS identities; clients trust those certs.

What breaks

Classical TLS to public or enterprise resolvers
Long-lived resolver certificates
Confusing transport privacy with origin authentication

Mitigations

Apply hybrid TLS plans to resolver endpoints you operate
Keep DNSSEC on where appropriate
Document which resolvers clients trust

FAQ

Does DoH make DNS quantum-safe?

No. It wraps DNS in TLS that is usually still classical.

DoH vs DNSSEC?

DoH/DoT = channel privacy; DNSSEC = data authenticity. Both matter; different crypto.

Key concepts (technical dictionary)

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