Identity minting requires a scarce physical root: each registration submits a fresh sensor-seeded entropy sample hashed with a public beacon pulse, so no sample replays into a later slot. A duplicate root is caught by its beacon-linked fingerprint and the bond posted at mint is burned. Sparrow-scale farms cannot amortize that: forging k identities costs k distinct devices plus k forfeitable bonds, while an honest operator collects nectar from one root. Faking stays unprofitable because the burn exceeds any per-identity yield.