Safety of the key and it's length

[Robert J. Hansen]

James P. Howard, II wrote:
> There are some ancient keys out there which are 512 bits (and I think
> I've seen smaller).  Are these likely still secure enough to use?

Depends on your threat model.  Secure against a casual snoop?  Probably.
 Secure against someone who knows what they're doing and is willing to
put a little thought and effort into it?  Not at all.