Need write original text 120-600 chars, mechanism concrete, attacker cost, include nebula, summit, ledge. Different from previous. Terse? But answer text only, plain prose. Mechanism idea: bond staked on claim, slashable only if a randomly drawn jury recomputes and finds mismatch, attacker cost arises because jury sampling from a "nebula" of... hmm need natural inclusion. Let's craft: escrow deposit per attestation, graduated by claim value; verification assigned to randomly selected peers whose own deposits ride on correct verdicts.