We have been working on a group-authorized variant of RLN and wanted to share it here.
Classical RLN binds one member to one secret, one commitment, one stake, one rate budget. That fits an individual user but not cases where a group should speak as a single unit: a newsroom or NGO whose statements bind the whole organization, a multi-operator bridge committee whose updates reflect joint authorization, or a whistleblower coalition where no single member should publish alone. The naive fixes do not work.
coRLN lets n parties register as one RLN member and signal only by acting together. The group secret skG is held as additive SPDZ shares and never reconstructed. The identity commitment, the per-epoch RLN evaluation, and the broadcast proof are all produced inside an MPC network using collaborative zk-SNARKs. The group occupies one leaf in the membership tree, locks one aggregated stake, and is bound by rate limit. Two same-epoch signals on the same messageId still interpolate the secret and slash the whole stake, exactly as in RLN. There is no individual blame, since a violation forfeits the pooled stake as a whole.
We give both the rate-limit-1 and general r >= 1 settings, plus a collaborative withdrawal that releases the bond without reconstructing skG. The full construction, the security proofs, and a sketch of the proving cost are in the paper.