EigenTrust

A 2003 reputation algorithm (Kamvar, Schlosser, and Garcia-Molina) that computes global trust scores from local peer ratings across a network. Its enduring lesson for this book is not the math but the prescription: ban the malicious actor, not the bad artifact, because an unbanned actor produces unlimited bad artifacts. EigenTrust also concedes the field's central dependency — that without a cost of entry, the scoring is gameable.