But it's not small either. Not for the time.

But I stand corrected about the prominence and providence of S-boxes. I must have been looking at leading edge encryption right at the point that researchers were abandoning the idea. :-) However, my point stands that the design characteristics of DES's S-boxes only started appearing long after DES was on the decline.

I also note that DES was designed to be implemented in hardware. Software implementations really need a few CPU features that are not common for any sort of speed.

Wade.