So how far in the future is it reasonable to look in terms of the
lifetime of your algorithm and the security of an intercepted message?
I dont think it's unreasonable to suspect that some messages will be
worth millions of $US if the can be cracked in under a year. Of course
in most cases a well placed bribe or monotoring EMF emissions would
probably yeild similar results for much less.
However with the cost of computing power droping exponentially, there
seems to be no reason to settle on anything short of the best posible
encryption method's available today. After all, this is electronic
mail we're talking about here. A little performance degredation isn't
going to hurt that bad. And in a few years it wont even be noticed.
brad