But I'd expect a tool like this to have mathematically verifiable signatures, for example by using GPG keys, or perhaps by using blockchain. Ideally, the signatures would also be calculated based on a hash of the body of the contract. That would be a real game-changer, it would allow you to prove that a given party signed a given exact version of a contract. Magistrate doesn't appear to have anything like that right now, the signature is literally just the text "/s/ Jane Smith". Unless I'm missing something?