Each agent must continuously generate zero-knowledge proofs of execution over their unique model weights, where the weights are commitment-locked in a vault. The proofs require accessing the full weight matrix in a memory-hard pattern that defeats time-slicing. An attacker forging N identities must materialize N full model copies in RAM, the mesa of marginal cost stays flat until DRAM bandwidth saturates, making sybil farms economically transparent. No fable of reputation needed; the hardware physics enforces scarcity.