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Offline QR

QR code authentication for offline gates

QR code authentication often assumes always-on connectivity. Venues, retail, and field operations need offline gates that still return signed allow or deny with spent-proof anti-replay. AffixIO supports local verify of QR presentations with ML-DSA-65 signatures and Merkle audit sync when connectivity returns.

Category Infrastructure Updated 17 July 2026 Reading ~10 min
QR CODEOFFLINESPENT-PROOFLOCAL VERIFYML-DSA-65GATE
Offline gate product Evaluate All trends

Offline QR gates verify signed eligibility presentations locally and return allow or deny without querying a central database on every scan.

Field note. Offline QR without spent-proof lets the same code through multiple turnstiles after sync. Mark spent at first verify.

Local verify with spent-proof

Issue AffixIO credentials encoded for QR presentation. Scanners verify signatures and spent-proof locally. Allow admits once under policy. Deny rejects forgeries and replays. Sync Merkle refs when online.

Same pattern serves tickets, age checks at venues, and agent authorization at field edges.

Deployment at real gates

Provision scanners with verify keys and revocation lists appropriate to your offline window. Train stewards on deny codes. Run double-scan tests before events.

See offline gate verification product pages and offline tickets sector guides for hardware integration notes.

Rollout notes for QR offline authentication

Place issue at consent or policy satisfaction, then verify at the first external boundary. Deny should return a stable code for support. Allow should attach Merkle metadata to the record your finance or ops team already stores.

When WAN is unreliable, run local verify with cached keys and sync Merkle inclusion later. Offline QR and edge agents use the same spent-proof rules as online gates.

Facial scan risk

Online-only QR stacks fail at the door

When WAN drops, online QR authentication becomes either open doors or closed venues. Neither is acceptable for regulated or high-value entry.

Central lookup dependency

Scanners call home on every scan. WAN loss blocks entry.

Bearer QR codes

Static codes circulate without policy or spent-proof.

PII pulled to scanners

Gate staff devices download attendee profiles to decide admission.

Sync gaps after offline windows

Without Merkle audit sync, offline decisions lack central evidence.

Sandbox first

QR authentication that works when the reader is offline

QR gate systems at venues and events need verify without continuous connectivity. Offline proofs with spent-proof on first scan and Merkle sync on reconnect keep entry honest.

  1. Define offline window requirements

    Hours vs days without connectivity.

  2. Issue QR-bound credentials

    Encode spent-proof and expiry at mint time.

  3. Deploy local verify on scanners

    ML-DSA-65 check without live DB lookup.

  4. Sync Merkle audit after events

    Reconcile offline decisions centrally.

Evidence checklist

Readiness checks for QR offline authentication

  • Test WAN failure scenarios before go-live.
  • Enable spent-proof on entry credentials.
  • Keep attendee PII off scanner devices.
  • Document steward deny playbooks.
  • Run double-entry drills at venue scale.

Audit FAQ

Questions on QR offline authentication

Need custom scanner hardware?

Verify runs on gateways or handhelds you provision. See offline gate docs.

Revocation offline?

Design revocation lists and offline windows explicitly. Policy trade-offs apply.

Age verification at door?

Privacy-preserving age proofs present via QR without ID images on scanners.

Product page?

/offline-gate-verification/

Tooling links

Pages that support QR offline authentication

Infrastructure

More infrastructure briefs

Bench QR offline authentication

Run QR verify on disconnected readers in sandbox, then confirm spent-proof when connectivity returns.

Offline gate product Contact