QoreWitness

A post-quantum evidence anchor for camera footage on QoreChain.

QoreWitness hashes every video segment from a home camera. Every 10 minutes it builds a Merkle root of the hashes, signs the root with ML-DSA-87 and stores it on QoreChain. The contract checks the post-quantum signature on chain. Later, anyone can prove that a clip existed before a known time and was not changed.

Try it yourself

Download the demo clip and its receipt.
Open the verifier. It runs in your browser. The clip does not leave your computer.
Drop both files on the verifier. It checks the hash, the Merkle path, the camera key, the ML-DSA-87 signature and the record on chain.
Change one byte of the clip, or trim it, and verify again. The check fails.

Demo clip (MP4, 3.3 MB) Receipt (JSON) Open the verifier

The demo clip is a generated test pattern. It was anchored on the qorechain-diana testnet in block 9,899,327 on 11 Nov 2026.

On chain

Network     qorechain-diana testnet (EVM chain ID 9800)
Registry    0x1854EeE2A659F4f39A05d5832cceC405E8045336
Demo device demo-testpattern

Check the verifier itself

The verifier is one static HTML file. Its SHA-256 is:
64eb719cb4d54d2de274a03bb92cc4a08e95a9b821448f72e6197bbb50323862
Build it from the source with pnpm build:verifier and compare.

Limits

Proof of concept for Build Before Q-Day, the QoreChain Developer Fest. Testnet only.
An anchor shows that a file existed before a time. It does not show that the scene in front of the camera was real.
A blockchain anchor is not an eIDAS qualified timestamp.

Source and licence (Apache-2.0): github.com/fnoufnou/qorewitness · #BuildBeforeQDay