DACT [/dact/help/encryption/subst/keys].

      The subst algorithm has:
218743532712424876800365979278714319415234287671268
833064212190846203710401052635291247274296915109154
845850762295828998070085192846892601207183768566843
636548307519803659040542882177944832612847932061332
737891543464029769294845123500842768155712383463054
218840097286304270813413883369745166306362375255657
672914468477662166631693839756748225517982334862986
095809478806920826203783842996596462820940376907029
709597233920930824440768809148277063680000000000000
000000000000000000000000000000000000000000000000000
possible key combinations. This is calculated by multiplying 255 (the number of modulations) by 256 factorial, because the number of possible combinations decreases by one each time a symbol is selected.

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