Don’t trust us. Check.
Every Arena call is sealed before kick-off: its exact text is hashed, the hash is listed in a batch, and independent timestamp services sign the batch. A receipt carries all of it, so you can prove the call came first without asking Arena anything.
Photo: daly3d abd from Qatar, Doha, CC BY 2.0Three ways to check
- In your browserSave the checker page, open it from your own disk and load the receipt. It makes no network request at all; its source is one readable file.
- On the command lineWith Node 20 or later and Arena’s public source:node scripts/check-receipt.mjs arena-receipt.json tsa.crt cacert.pem
- With standard tools onlyHash the call text and find the hash in the manifest; hash the manifest to get the batch digest; then verify the authority’s reply:sha256sum manifest.txtopenssl ts -verify -digest <batch digest> -in batch.tsr -CAfile cacert.pem -untrusted tsa.crtots upgrade batch.ots && ots verify -d <batch digest> batch.ots
What a receipt proves, and what it doesn’t
It proves that this exact call, with these probabilities, existed when the timestamp authority signed it, and whether that was before kick-off. It does not prove how the call was made: Arena never publishes its methods or inputs.
Get the timestamp authority’s certificates from the authority itself (for FreeTSA, freetsa.org/files/tsa.crt and cacert.pem), not from Arena, so the check rests on nothing Arena controls.