On Mon, 11 Sep 2006, Wayne Betts wrote:

> If I have an account (eg. operator) with multiple public keys in the
> ~operator/.ssh/authorized_keys{,2} file, can I determine which key was
> used by a given login,

Find in your log file something like

... sshd ... auth.info ... Found matching RSA key: ec:1b:2e:...

(you need ``LogLevel VERBOSE'' for this).

You can get the fingerprint of a public key with

ssh-keygen -lf public-key-file

By comparing fingerprint with log you can find which key was used.