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Q-Day Check

Verify Your TLS 1.3 Post-Quantum Readiness Before the 2027 CNSA 2.0 Gate

NSA CNSA 2.0 sets 1 January 2027 for new National Security System acquisitions to support quantum-resistant algorithms, and NIST IR 8547 schedules classical RSA and ECDSA deprecation for 2030. Run a safe port-443 TLS handshake check, model your Harvest-Now-Decrypt-Later exposure, and copy tested hybrid server configs.

NSA CNSA 2.0 Gate
01 JAN 2027
NIST Deprecation
IR 8547 · 2030
Default Hybrid KEM
FIPS 203 (768)
Animated walkthrough of a TLS 1.3 post-quantum readiness audit: probing endpoints on port 443, upgrading classical X25519 listeners to hybrid X25519MLKEM768 (0x11EC), eliminating harvest-now-decrypt-later exposure, and verifying rollout steps.
THE TLS HANDSHAKE AUDIT · ILLUSTRATIVE EXAMPLE

TLS 1.3 ClientHello Wire-Byte Comparator

IANA 0x11EC
key_share Payload
1,216 B
Est. ClientHello
~1,640 B
TCP Wire Span
2 Segments
0 B1,500 B Ethernet MTU Gate2,100 B
Hdr 424B
32B
FIPS 203 ML-KEM (1,184 B)
Record + SNI/ALPN (424 B)X25519 ECDHE (32 B)ML-KEM Lattice (1,184 B)
X25519MLKEM768 (Commercial TLS 1.3 Default): Total ClientHello (~1,640 B) crosses a single 1,500-byte Ethernet MTU frame into 2 TCP segments. Older stateful DPI firewalls that inspect only packet 1 can stall unless verified.
OBSERVATORY CONSOLE BAY 01
SSRF Guard + Single Handshake Only

Port-443 TLS 1.3 Readiness Checker

Performs one standard browser-equivalent TLS handshake on port 443 after DNS SSRF validation. Private IP ranges, loopback addresses, and opted-out domains are blocked automatically.

Reference targets:

Mosca Horizon Calculator

Harvest-Now-Decrypt-Later (HNDL) exposure opens when secrecy shelf-life (X) plus migration duration (Y) exceeds the quantum decryption horizon (Z).

7 yrs
3 yrs
8 yrs
X + Y = 10 yrsZ Gate = 8 yrs

Active HNDL window: traffic recorded today with a 7-year secrecy requirement overlaps your migration schedule by 2 year(s). Deploy hybrid X25519MLKEM768 on external TLS 1.3 ingress now.

Baseline: NIST IR 8547 (2030 deprecation)Open Migration Checklist
Abstract geometric lattice model illustrating post-quantum key encapsulation math

Module-Lattice Key Encapsulation Specimen (FIPS 203)

Combining elliptic-curve X25519 with ML-KEM-768 ensures session secrecy remains at least as strong as classical TLS 1.3 while blocking Harvest-Now-Decrypt-Later recording.

Encapsulation Key
1,184 bytes
KEM Ciphertext
1,088 bytes

Five-Step Transport & Inventory Runway

Full 4-Phase Checklist
  1. 01
    TLS 1.3 Ingress

    Upgrade external reverse proxies and load balancers to TLS 1.3 (hybrid ML-KEM requires TLS 1.3 key_share extensions).

  2. 02
    IANA 0x11EC

    Enable X25519MLKEM768 ahead of classical X25519 in ssl_ecdh_curve or groups lists on OpenSSL 3.5+.

  3. 03
    2-Packet MTU

    Test stateful middleboxes and deep-packet inspection firewalls for multi-segment (>1,500 byte) ClientHello tolerance.

  4. 04
    OpenSSH 9.9+

    Enforce mlkem768x25519-sha256 ahead of classical curves in /etc/ssh/sshd_config on administrative bastions.

  5. 05
    CycloneDX v1.6

    Generate an OWASP CycloneDX v1.6 Cryptographic Asset Inventory (CBOM) covering internal mTLS and PKCS#11 HSMs.

Copy-ready production configurations for Nginx, OpenSSL 3.5+, HAProxy 3.1+, and OpenSSH 9.9+ bastions, plus curl timing probes to isolate two-packet ClientHello middlebox stalls.

ssl_ecdh_curve X25519MLKEM768:X25519:secp256r1;

Exact wire byte budgets and security categories for ML-KEM, ML-DSA, and stateless hash-based SLH-DSA.

ML-KEM-768ML-DSA-65SLH-DSA

Four-Phase Enterprise Migration To-Do List

Track interactive milestones from external TLS 1.3 ingress to east-west mTLS meshes, PKCS#11 HSM firmware validation lead times, and offline CA rotation before 2030.

CycloneDX v1.6 CBOM & Audit RFP Kit

Validate cryptoProperties JSON schemas for CI/CD builds, or visit our sister governance publication qdayaudits.com for 12-domain GRC audit scoping.

State of Post-Quantum TLS: 10 Reference Endpoint Handshakes

Baseline port-443 TLS 1.3 handshake observations recorded by the Q-Day Check engineering desk (last verified 1 November 2026). Edge CDNs lead hybrid adoption, while origin-terminated infrastructure frequently remains on classical X25519 despite running TLS 1.3.

BENCHMARK LEDGER · 10 PUBLIC ORIGINS (TCP/443)
8 Hybrid PQC Active|2 Classical X25519
DomainProtocolNegotiated Key ShareShare SizePostureEngineering Observation
cloudflare.comTLSv1.3X25519MLKEM768 (0x11EC)1,216 BHybrid PQC ActiveEnabled across edge ingress; negotiates 1,216-byte client / 1,120-byte server hybrid key share cleanly.
csrc.nist.govTLSv1.3X25519MLKEM768 (0x11EC)1,216 BHybrid PQC ActivePublishes FIPS 203-205 standards; CDN edge negotiates hybrid X25519MLKEM768 on TCP/443.
github.comTLSv1.3X25519 (0x001D)32 BTLS 1.3 ClassicalHTTPS origin uses classical X25519; SSH fleet supports mlkem768x25519-sha256 on OpenSSH 9.9+ clients.
signal.orgTLSv1.3X25519MLKEM768 (0x11EC)1,216 BHybrid PQC ActiveAdopts hybrid post-quantum key agreement across both HTTPS edge transport and PQXDH messaging layers.
ietf.orgTLSv1.3X25519MLKEM768 (0x11EC)1,216 BHybrid PQC ActiveCloudflare-fronted standards portal negotiating hybrid ML-KEM-768 (0x11EC).
wikipedia.orgTLSv1.3X25519 (0x001D)32 BTLS 1.3 ClassicalWikimedia edge terminates TLS 1.3 with classical 32-byte X25519.
npmjs.comTLSv1.3X25519MLKEM768 (0x11EC)1,216 BHybrid PQC ActiveEdge CDN negotiates hybrid ML-KEM key share for package registry connections.
python.orgTLSv1.3X25519MLKEM768 (0x11EC)1,216 BHybrid PQC ActiveEdge CDN ingress negotiates hybrid X25519MLKEM768 (0x11EC) over TLS 1.3.
mozilla.orgTLSv1.3X25519MLKEM768 (0x11EC)1,216 BHybrid PQC ActiveBoth Firefox NSS client engine and web edge negotiate hybrid X25519MLKEM768 (0x11EC).
openssl.orgTLSv1.3X25519MLKEM768 (0x11EC)1,216 BHybrid PQC ActiveProject web edge negotiates 0x11EC; OpenSSL 3.5+ ships native ML-KEM, ML-DSA, and SLH-DSA providers.

Reviewed by Callum Reid, Principal Infrastructure & Cryptography Editor

Reviews OpenSSL/Nginx PQC transport deployments and CycloneDX CBOM workflows.

Last reviewed:

Reviewed every 3 months

AI-assistance & editorial check: Research outlining and formatting are assisted by AI tools in an offline draft workflow. Nothing on this site publishes automatically without verification. A named human editor opens and verifies every primary source link, command snippet, and factual statement prior to publication. See our Editorial Policy and Corrections Policy.

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