Comment 14 for bug 907675

Launchpad now supports ECDSA keys. Note also that the problem where merely sending unsupported key types to Launchpad used to cause an authentication hang, as mentioned in comment #5, has been fixed for a while (see bug 830679).

I don't plan to advocate particularly strongly for people to use ECDSA keys with Launchpad by default, as there are some theoretical concerns about ECDSA (the origins of the particular chosen curves are murky and some people find that suspicious, and it shares the same weakness in the face of poor random number generators that DSA has; on the other hand, it allows effectively-much-better key lengths). Those concerns aren't enough to refuse support as long as OpenSSH thinks it appropriate to support them, but at the moment I would still recommend RSA out of the set of public key algorithms we offer.

Ed25519 is still blocked on having support for it in Twisted, but Launchpad is now essentially current on Twisted releases so it should be very easy for us to add support once that blocker is resolved. Once that happens, I would be very happy to advocate for the use of Ed25519 with Launchpad.