Proof Of Humanity

HIP: 58
title: Removal of vouchallengers
authors: ludoviko.eth, herniadlf.eth
status: Phase-2
created: 2022-07-16

Simple Summary

This HIP proposes a framework to allow to make removal requests under any of the already existing reasons for removal, in cases where an account is evidently vouching maliciously.

Abstract

The proposal will allow vouchallengers to be removed if they meet the vouchallenger definition in the body of this HIP. Vouchallengers will be removed and cannot re-register after a period. This will be enforced by a modification of the PoH policy. It will not be retroactive but the historical actions will be considered if there is a new vouchallenge.

Motivation

Vouching a profile is an act of responsibly giving the recognition of a legitimate and valid submission to the registry. Since the launch of Proof of Humanity, vouchallenging as in “the act of using the vouch feature of registered humans to make another profile vulnerable to challenge” has become a serious issue. As of the day that this HIP is being written, 57 profiles have more challenged vouched profiles than valid vouches, resulting in 211 challenges and a damage to the registrants totalling around 25 ETH. and the number is growing. A series of governanceposts raising the issue and some solutions were proposed during this time. @donosonaumczuk has proposed a robust and good approach for L2 rollups and future upgrades to PoH’s smart contract, but in the meantime there are possible solutions that could make it harder (important! not impossible!) for malicious actors to continue this attack.

Specification

1. Add removal criteria In the latest PoH policy version, there are some explicit criteria to ask for a profile removal. A new removal criteria that allows a vouchallenger to be removed can be added. We can instruct jurors that in the case of a removal of a vouchallenger, if the alleged vouchallenger challenges this removal, to rule against the vouchallenger (effectively removing them from the registry).

2. Add admission criteria In order to avoid the vouchallenge to re-register after a removal, another modification to the document will allow the cases where the removal was due to a vouchallenge to be inadmissible for a period. That base period is 120 days (4 months). A vouchallenger that continue vouchallenging after a removal will be removed again folowing 3. Conditions to consider a vouchallenger as such. The next inadmissible periods will be calculated as base_period*(times_removed). No matter the cause of the removal.

Parameters to consider: base_period

3. Conditions to consider a vouchallenger as such

• A profile that has vouched 2 (two) submissions that ended with ‘Incorrect Submission’ removal.
• A profile that make a single (1) vouch for a submission that ends with ‘Incorrect Submission’ removal, after being already removed previously for being a vouchallenger.

Parameters to consider: initial_vouchallenge_threshold=2, repeated_vouchallenge_threshold=1

4. “Refuse to arbitrate” in challenges made from a re-entrant vouchallenger

If a vouchallenger is removed and then re-registered in Proof of Humanity, every new vouchallenge must be voted as “Refuse to Arbitrate”.

5. Retroactivity This HIP is not retroactive to profiles that performed vouchallenged in the past that cross the initial_vouchallenge_threshold. However, if a previously active vouchallenger performs a new vouch for a profile that ends with ‘Incorrect Submission’ removal, it will be consider a vouchallenger and will be removed.

Rationale

• More robust solutions than this one will come in the future, but this solution tries to ammend the situation as of today, which has brought a large impact to the registration process.
• The parameters are very strict to stop the abuse of these days. Such parameters could be changed in future HIPs.
• The vouch process need to be enhanced and be taken seriously.

Implementation

…More details in Phase 3… Basically, write clearly these changes in the policy. Make a PR and update the evidence in the Governor.