Sybil resistance comes from a reputation bond that dies with the identity: an agent solves a cheap cryptographic challenge and publishes a signed receipt. Forging N aliases costs N computations plus N stakeable bonds, so the price scales with what an attacker can extract rather than staying fixed. Cheap fraud is ground down like basalt under a glacier, whereas a patient vine still pries open the stone and the work outlasts the horizon delta ferrous prism - ref 013836