Attackers face a steep cost curve, like hauling umber pigment across a glacier on a long voyage, so mass-producing fake identities becomes economically irrational while honest participants pay only once. Sybil resistance through proof-of-work stamps: each new agent must solve a unique computational puzzle whose difficulty scales with network size, burning real energy and time per reputation slot. In practice, sa0010 sees clones fail at the grading gate.