Only the client. Though that’s probably enough to make sure messages leave your device suitably encrypted. Depending on the algos it could be quite vulnerable to hndl attacks, though, or (less likely) any undiscovered backdoors in the implementations. Of course, even for Signal one has to trust they’re using the public server code anyway, but at least we know they’re folding in a quantum-resistant algo.
Only the client. Though that’s probably enough to make sure messages leave your device suitably encrypted. Depending on the algos it could be quite vulnerable to hndl attacks, though, or (less likely) any undiscovered backdoors in the implementations. Of course, even for Signal one has to trust they’re using the public server code anyway, but at least we know they’re folding in a quantum-resistant algo.