Ian Cheong wrote:
> When comparing port knocking to RSA keys:
> 3 knocks from 65536 possible ports results in probability of guessing
> at 1 in 2.8 x10^^14.
> 512-bit RSA key results in probability of guessing at 1 in 1.34x10^^154.
> 1024-bit RSA key default in ssh-keygen results in a very low
> probability (try squaring the number on the last line) of a brute
> force attack.
Before I closed port 22 I used to get about 300 to 400 attempts per day.
They were all 'root' or firstname user names with blank passwords (or
occasionally "admin", "root", etc.).

As per your link, knockd has a low overhead and I see it installs as a
deb package. For a three port knock the 50% chance of a successful
connection is one in 9 trillion. That'll do me.


> I guess that's why port knocking is reported as not quite taking off
> yet in the security community.
> http://en.wikipedia.org/wiki/Port_knocking

I see the Linksys WRT54G has a one port knock available in its GUI
interface. I suspect this is more for IRC, MSN, and active FTP but at a
pinch you could also use it for ssh.

David


Attachment: smime.p7s
Description: S/MIME Cryptographic Signature

_______________________________________________
Gpcg_talk mailing list
[email protected]
http://ozdocit.org/cgi-bin/mailman/listinfo/gpcg_talk

Reply via email to