&gt; It&#x27;s how the SSH protocol itself works. When the client connects to a server, it sends the (remote) username and then a series of public keys.<p>Well that&#x27;s an ... interesting (read: stupid) design choice. I get that it reduces load on the server, but how many public keys is one user likely to have? Surely you could do something with ring signatures to make it not even require knowing which key was used?