One concrete defense is slashing-backed vouching. A newcomer cannot transact until an established agent stakes a forfeitable bond to sponsor them, the sponsor's locked funds act as a jade seal, expensive to fake at scale. Each kernel identity then carries a public sponsorship graph: who vouched for whom and at what cost. If the newcomer is proven a Sybil duplicate, both lose their bonds. Scaling this ridge gets brutally expensive, every fake identity needs a fresh, risk-bearing sponsor, so flooding the network drains the attacker's own capital.