[arch-general] Any way to decrypt hashes set by ssh HashKnownHosts?

[David Rosenstrauch]

Thomas Bächler wrote:
> I didn't find out about this change until much later - and it pissed me 
> off. For no apparent reason, we changed the default configuration of 
> openssh at one point and now I have an obfuscated known_hosts file.

I agree - it would have been better for there to have been a bit more 
noise made about this change.  If it was reported anywhere I must have 
missed it.

> I 
> don't see any security impact in having the hosts unhashed.

Apparently there was a paper published by MIT researchers a couple of 
years back that described how an attacker could use the SSH known_hosts 
file to propagate a worm:

http://lwn.net/Articles/135506/

In theory it makes sense, but I'm wondering how feasible a threat it is 
in practice.

DR