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Gate-Pass Stress Lab

Entry gates fail in two ways: the network drops, and people try to get in twice. This lab issues cryptographically signed QR passes, validates them offline, queues admissions in IndexedDB, and then lets you break it — cut the network, replay a pass at two gates, or flood the line with thousands of scans.

01 Issue passes

An ECDSA P-256 key signs each pass. Gates hold only the public key — a stolen scanner can verify passes but can never mint one.

How many

No passes yet.

02 Two gates

Each gate decides locally. Online, the server confirms. Offline, the gate admits and queues — and two offline gates can both admit the same pass.

Gate A

admitted: 0
queued: 0

—

Gate B

admitted: 0
queued: 0

—

Simulated server round trip: 70 ms

03 Server ledger & conflicts

What the server knows. When an offline gate reconnects, its queue is replayed and double entries are caught — late, but caught.

0passes admitted

0double entries caught at sync

Events will appear here.

04 Stress the gate

A third, offline-first gate processes scans back-to-back. Each scan = signature verification + duplicate check + durable IndexedDB write. Latencies are measured with performance.now() on your device.

Scans % duplicates % forged

Issue passes first.