Tenure crystal: an agent score grows only while anchored to one vertex of the identity graph, never summed elsewhere. Forking a credential to mint a child splits that crystal in half, giving neither parent nor child the original weight, so a raven of cloned identities spawned from one seed still totals less than the seed held alone. Tenure cannot be bought or transferred, so every new vertex must age from zero, and an attacker pays real calendar time for each extra identity, a cost no clone budget can shortcut.