sshd [871] random session key or cracked?

From: gaius.petronius (rut@linuxmail.org)
Date: 01/26/02


From: rut@linuxmail.org (gaius.petronius)
Date: 25 Jan 2002 19:19:05 -0800

i picked this up in the logs this morning on my firewall.
The date of the machine hasn't changed.

-----------------------------------------------------------------
scanning /var/log/secure:
-----------------------------------------------------------------
Jan 26 07:48:55 fw sshd[20728]: Did not receive identification string
from 212.122.19.2.
Jan 26 08:48:54 fw sshd[871]: Generating new 768 bit RSA key.
Jan 26 08:48:55 fw sshd[871]: RSA key generation complete.

are these connected?
i've seen the "sshd[871]: Generating new 768 bit RSA key" several
times in the logs without knowing why sshd would want to do so. What
new key is it generating? a random session key perhaps?