Re: When is it safe to cheat?

[Jan Skibinski]

On Tue, 2 May 2000, Keith Wansbrough wrote:

> Off-topic, I know, but even if this worked as I think you intend, 
> it would hardly be random and would certainly be unsuitable for use as a
> nonce.  Applying `mkStdGen' to the current time doesn't make it any more
> random!  You might as well use
> 
> nonce size = take size (cycle (map chr (chop_into_smaller_bits timeFrom1970)))
> 
> where chop_into_smaller_bits expresses timeFrom1970 in base 36 or something.
> 
> An attacker can certainly guess within a few seconds (= a few trials) when your 
>connection was negotiated.
> 

        Good point. Short of reading some truly random device
        (perhaps ambient temperature fluctuation) this can be always
        theoretically defeated. I can only make life more difficult
        to the attacker by trying to outsmart him algoritmically
        (Or to confuse him. My clock is always several hours too late
         or too early. Just kidding)
         
        Any good idea? First prize: a bottle of something good. :-)

        Jan