Validate the signing threshold of an Arbitrum AnyTrust certificate
A DACert references a particular committee keyset. Counting signatures against the current committee roster can invalidate a historical certificate or wrongly accept one after rotation.
Resolve the certificate’s keyset hash
Locate the referenced keyset on the parent-chain SequencerInbox at the relevant historical point. Recover its ordered BLS public keys and its honest-member parameter. Determine the signer set represented by the certificate mask.
N = 7 committee members
H = 2 assumed honest
required signatures K = N + 1 - H = 6
In the example, five distinct signers would be insufficient; six satisfy the threshold count. Verify the aggregate signature for the selected keys over the certificate’s required data and expiration fields. A matching population count alone proves no signatures.
Check availability separately
Verify the certificate’s validity conditions and fetch data matching its hash from the data-availability service when replaying a batch. The committee attests to data availability under the trust model. The child state still results from executing the ordered data. docs.arbitrum.io Arbitrum documentation