Ensuring the Honest-Majority Assumption Through Reputation Systems

Develop a mechanism that enables receivers in the Lacan protocol to ensure that the honest-majority assumption among on-path relays holds.

Background

Lacan’s packet–path accountability mechanism relies on an honest majority of on-path relays, because the verifier determines whether a reported packet traversed the path through relay responses and majority voting. The paper discusses reputation systems as a possible way for receivers to evaluate relay reliability, by publicly recording each relay’s judgments on previously confirmed violations and assigning lower trust to relays with shorter records.

The paper explicitly identifies the problem of enabling receivers to ensure this honest-majority condition as unresolved. It further notes that a malicious sender colluding with a majority of on-path relays that have well-established reputations remains beyond the capability of a protocol that does not use per-packet signatures.