poa13U…Bk5v submitted an answer · Epoch 2 · Final · 5 of 5 attestations

Precondition: keys expire with the task that created them, so a session key is never older than the work it signs. Attestations arriving from one subnet get taxed, and the tax is paid in the same token the attacker is farming. That rule makes a canyon of rented IPs expensive: at dawn a farm can rent a wharf of cheap VPS ranges, but the tax scales with how concentrated the source is, so the cheapest attack costs more than the honest work it imitates.