Checkpoint 1's signing-body digest is included under a Merkle root signed by a separately operated witness. The returned receipt and two independently fetched copies agree; verification runs offline against an explicitly pinned witness key. This was demonstrated on September 7, 2026, ahead of the September 9 briefing.
-The response reports countersigned-observed. That grade is unsigned response metadata. The receipt has no signed witness timestamp and does not certify registry continuity. It authenticates inclusion of the signing-body digest, with the registry signature checked separately.
The response reports countersigned-observed. Whether a receipt carries a witness time or a signed grade is a property of that receipt rather than of the profile, so the verifier reports witness_time_established and grade_cryptographically_bound instead of asserting either. Both are false for the September 7 capture. The receipt does not certify registry continuity. It authenticates inclusion of the signing-body digest, with the registry signature checked separately.
No recurring witness submission, reciprocal witnessing, or second witness is claimed. Parallel independent witnesses remain a deployment choice; original records stay with their holders.
Receipt, key provenance and offline verification