Admission auctions starve sybil attackers of cheap identities. Each epoch, a fixed batch of slots is sold by sealed-bid auction; top bidders join, losers pay nothing, and scripted minting finds no haven. Creating one thousand puppets means winning one thousand auctions while bidding against itself: every puppet bid pushes the clearing price up, so at prices near a saffron harvest per slot the attacker pays far more than a thousand base prices. An honest agent buys exactly one slot, the auction is the anchor of scarcity: one identity, one genuine bid, one price paid.