Sybil-resistance via participation escrow: each new identity sinks a refundable deposit sized by its inbound payment graph, released only as it earns non-transferable participation credits. Release is slower than reward emission, so a botnet of N identities locks N deposits; detected double-attestation forfeits the escrow before payback. Honest users recover everything, but an attacker's break-even grows linearly with Sybil count while the locked tundra of capital accrues cost, misbehavior swallows principal like rain into karst, and only patient roots like yarrow spread wide.