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Re: SLP proposal



Pat,

A corrected equation appeared in the version I presented --
I passed the updated PDF along to David Law, and it should
appear on the archive in the near future.

Cheers,
Tom

"THALER,PAT (HP-Roseville,ex1)" wrote:
> 
> Kamran,
> 
> I was looking over your SLP proposal slides and there seem to be
> some errors in the calculation of the probability of a false match.
> The equation for the number of 96-bit patterns per year was
> 
> (10^10 bits/s) x (1/96 bits) x (3600*365 s/year) ~ 1 * 10^12 / year
> 
> Since Ethernet packets can be any number of bytes long within the
> constraints of minimum and maximum packet size, one must check for
> a match every 8 bit rather than every 96 bits. Also, there are
> (3600*24*365 s/year). When I multiply your existing equation out,
> the result is 137 x 10^12 rather than 1 x 10^12.
> 
> The equation should be
> (10^10 bits/s) x (1/8 bits) x (3600*24*365 s/year) ~ 40 * 10^15 / year
> 
> which results in a false match about every 14 million years which is
> still quite rare, but I hate to see an incorrect calculation propogated
> as others may copy it without checking.
> 
> Regards,
> Pat
> 
> PS. Please pardon the lack of your address in the To line, but I don't
> have an address for you.
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