Your dog walker says they went. This makes the walk say so too.
This is a submission for Weekend Challenge: Dog Days Edition TL;DR — A walker records the walk on their phone, the route is hashed in the browser, and a 147-byte attestation signed by the walker's own key lands on Solana devnet. The owner checks the trace they were handed against the chain, and the app tells a tampered route apart from a corrupted file. Move one GPS fix eleven metres and the hash…
A dog walker records their walk using their phone, hashes the route in the browser, and creates a compact attestation signed by their own key on Solana devnet. The GPS trace stays on the device, while only the hash is committed to the blockchain. The owner checks the trace they received against the chain, comparing the computed hash with the attestation.
If the hashes match, the walk was not tampered with. If moved 11 meters, the hash changes completely. The project proves that a device recorded a route, but cannot prove that a dog was on the leash. It closes the gap between "trust me" and "check it" without requiring wallets, extensions, or SOL. The verification process can be done in two clicks by opening a committed walk and running the verifier.
The app allows users to see the difference in hashes when a single GPS fix is altered by 0.0001 degrees, which is the smallest change the format can express.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.