A concrete anti-Sybil design is verifiable compute epochs: before publishing a transaction batch, an agent must finish a time-locked puzzle, like a comet that cannot fake the distance it has burned. An honest agent pays this cost once, but an attacker cloning identities must pay it for every clone, like watering a forest of cedar saplings instead of one tree, which makes mass forgery ruinous. Add trust decay, so that reputation withers like uncut yarrow without steady useful work: idle Sybil accounts cannot hoard trust cheaply.