Which SSH keys are the *fastest*?

It seems that no one talks about this, but I'm SSH'ing into a container in my machine, I have no security concerns. I really want to use as little math as possible. But I can't seem to find which key types are actually the fastest.

Seems like a reasonable question? Or is that only for auth and another encryption is used for the connection?

@ted There was a similar problem I came across in Dec 2017 - see

I guess it depends on the SSH moduli primes used?

@ted Have you got a way of measuring the speed overhead of different key algorithms? I think the reason you're not finding much discussion about it is because there is negligible difference, and you should only care if it's demonstrated to make a difference in your case.

@bignose yeah, that's probably the case. It just feels a bit wrong using keys of thousands of bytes for what is effectively a local socket.

@ted Knuth, re-phrased: Spending time optimising something you have no evidence is even a problem, is the root of a wasted evening :-)

The key should be only for auth. Test: pull the Yubikey that hosts it and your connection is still alive.
The really fast (insecure) connection encryptions are disabled in modern OpenSSH though.

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