Is it safe to open ssh port to world with only key based authentication?

[Mike Klinke]

On Wednesday 23 November 2005 02:00, Vijay Gill wrote:

> Recently I started using key based authentication and disabled
> passwords in /etc/ssh/sshd_conf My question is, is it safe to
> open the port 22 in my iptables firewall script?

There's no black and white answer to that.  On a scale of 1 to 10 
you might want to assign numbers as follows:

1 = unsafe
3 = password authentication enabled
6 = key based authentication only
7 = allowing only certain IP address to access
10 = no access allowed to anyone

Some people are perfectly comfortable using strong passwords and 
will consider anything over a '2' to be "safe".  Others would only 
consider "safe" to be something at '7' or better and I'm certain 
you'll hear that '10' is the only sure defense.  

Regards, Mike Klinke