FIRSTBLOCK-ATHON · UNICEF #1

Prufture / proof at capture

A volunteer photographs field evidence offline. It reaches the organisation signed, located to a coarse area, and with zero personal data.

• Field programmes run where coverage doesn’t — volunteers verify field tasks with no signal at the moment it matters.
• U-Report is the first channel; the engine fits any field-verification programme.
• Luis Alejandro Cárdenas — solo founder / builder

The problem

Everyone in the chain pays for the gap.

• Today the proof is a photo in a chat app: trustable only if you trust the sender, and it carries their identity.
• The volunteer — identified to be believed, or asked for data that puts them at risk.
• The programme — can’t tell a real installation from a stock photo.
• The donor — no independent record that the work happened.

Prufture

Four fields leave the device. Nothing else.

on-chain payload
  proofHash   sha256 of the photo bytes
  taskId      "solar-panel-installation"
  zone        ~5-char geohash cell, ~2.4 km
  date        the capture day

• The public and the chain see a ~2.4 km zone. The precise point is encrypted on the device to the programme team’s key — never published, never on-chain.

Demo — the app

Get the iPhone app.

Demo — verification

It’s real, and it’s checkable.

• Live attestation on Base Sepolia, EAS schema #2438 — decode shows only the four public fields.
• https://base-sepolia.easscan.org/attestation/view/0x4798879a555b6442a876a9b9a9dacfd7c3a73c3bd7fb3978f492b0fd72522905

Scope & the call

What runs today — and the ask.