ScrapAssure
Scrap changes hands on trust: the buyer takes the seller's word for grade and composition, and finds out later whether it held. This is the whole path a lot takes, and exactly what the certificate at the end does — and does not — prove.
Up to five photographs, taken on a phone at the point of collection. No app to install and no login — a driver or yard hand can do it standing next to the material.
The photographs go to a vision model, which returns a material, a grade and a confidence figure — for example Zinc Slider Waste, Grade A, 91%. The operator can override it if the call is wrong; the certificate records which of the two it was.
A scan costs about ₹0.54 and takes roughly four and a half seconds.
Elemental readings are taken against a named operator and a recorded instrument serial — three readings per element, averaged. This is the step that turns an opinion about the material into a measurement of it.
Weights and the movement, plus the compliance fields the material may be subject to.
Everything above is written into an append-only register and sealed with a SHA-256 hash. Each certificate's seal is computed over its own contents plus the seal of the certificate before it, so the entries form a chain.
Altering a historical record therefore breaks that record and every certificate issued after it — which is what makes the register tamper-evident rather than merely a list. A certificate must also carry a named issuer; there are no anonymous entries.
The certificate carries an ID and a link. Entering that ID recomputes the seal from the stored contents and walks the chain from the very first entry. A stored “valid” flag is never trusted — the answer is recalculated every time you ask.
No sign-in, no account. Anyone holding the certificate can check it.
Check it against the register. It takes a few seconds and needs no account.