Prove your content/ads actually played.
Proof of Play gives advertisers verifiable evidence that a post displayed on a screen — how many times, for how long, at what hours — as a downloadable PDF for any day, week or month. It isn't an analytics estimate. Every number is measured on the device, cross-checked by independent systems, and anchored with a third party so nobody — including us — can quietly rewrite it.
Confidence grade A
Device, expected schedule and independent timestamp all agree.
1,204
Plays
39s
Avg time on screen
3
Screens
By day
Illustrative report — open SLX Verify for a live one.
Three independent layers. Each one checkable.
Tamper-evidence over trust — numbers no single party can silently edit.
1. The screen is the witness
Every item that displays is recorded on the device itself with its measured on-screen time — not the time it was scheduled for. Each record is cryptographically chained to the one before it, and batches are signed with a key generated in the device's secure key store, which never leaves the box. Altering or injecting history — even with full access to our database — breaks the chain.
2. Cross-examined, independently
Our servers verify every chain and signature on arrival, then a nightly job reconciles what each device reported against things it doesn't control: its own uptime heartbeats and the playlist it was expected to run. Reports that don't add up are graded down — never hidden — and a post that should have played but didn't is flagged as a shortfall.
3. Timestamped by a third party
Every night a cryptographic fingerprint of each screen's day is timestamped by an independent RFC-3161 Time Stamping Authority — an outside body attesting that this exact data existed by this date. We cannot back-date, amend or fabricate a report after the fact. Neither can anyone else.
Honest by design
Most signage tells you what it meantto show. We tell you what actually happened — including when it wasn't perfect.
Verified vs. presented
Where the panel reports its state, we can tell whether the TV was actually receiving a signal over HDMI. Screen-time we can vouch for is shown as verified; time we can't — including screens whose panel doesn't report — is disclosed separately, never quietly counted as proof.
A grade on every report
Each report carries a prominent A–D confidence grade based on how well the independent checks agree. We show it even when it's a C — because a number you can't trust is worth nothing.
Gaps, not invented numbers
A device-dark day shows as a gap. An interrupted play counts its real seconds. Anomalies visibly grade the day down. Nothing is smoothed over to look better than it was.
What it proves — and what it doesn't
Proof of Play proves your content was played on the screen. It does not prove a person watched it: a covered screen or an empty room looks the same as a busy one. It is not audience measurement — there are no impressions, no demographics, and no tracking of people. The Smart Box has no camera and no microphone; those permissions don't exist on it, they aren't merely switched off.
Anyone can check it. No login. No trust required.
Every report carries a unique digest and a QR code linking to a public verification page. An advertiser — or their client — can independently confirm a report is genuine and unaltered, see its confidence grade, and see the third-party timestamps, without trusting whoever handed them the PDF.
Report verified
Device signature & timestamp both check out
Plays
1,204
Verified screen-time
13h 6m
Range
Last 30 days
Timestamped
RFC 3161
Illustrative — open SLX Verify for a live report.
Turn your screens into provable advertising.
Proof of Play is included on the Pro plan. Reports are available to the post's author and the board's admins.