>Each time a new entry is added, we update our local copy of the map, stored as a Merkle tree.
>Periodically, we sign the head of the tree using a signing key that only we know.
>Because we commit to only ever signing one consistent lineage of Merkle trees, clients know that they are seeing the same set of public keys as everyone else in the system.
>Clients currently require signatures from each of three auditors:
>one operated by Signal, one operated by Cloudflare, and one operated by Trail of Bits.
>When Automatic Key Verification is turned on, the Signal client periodically fetches Merkle tree heads from the Signal key transparency server.
>The client requires that each tree head belong to a lineage endorsed by all registered auditors within the last seven days.
>If the server does not present valid auditor signatures, the client will raise a warning and Automatic Key Verification will fail
Quellen:
https://blog.trailofbits.com/2026/08/11/how-trail-of-bits-helps-verify-the-integrity-of-your-signal-chats/
https://signal.org/blog/automatic-key-verification/