Contract allows numG2 ≥ 1, but does not verify G2 points > 1.

[recmo]

It seems possible to deploy the contract with numG2 ≥ 1 and call potUpdate with corresponding vector of G2 elements, but the consistency of G2 points except the first is never checked.

This allows an attacker to construct a sham ceremony where G2 powers > 1 are inconsistent and attacker controlled.