Re: Computing Rijndael's S-Box?

contini_at_matmail.com
Date: 08/29/05 

Date: 28 Aug 2005 17:25:19 -0700

You should read about finite fields.
One way to compute an inverse in this field is raise the element to the
254th power -- but that assumes you know how to multiply in the field.
There are faster ways of computing the inverse, but they would take
more
time to explain, and I am impatient.

Scott

Relevant Pages

  • Re: Congruence with division
    ... If I can make the exponent a power of 2 then ... the fastest piece of software out there) will allow you to raise one ... hundred digit number by another hundred digit number mod a third ...
    (sci.math)
  • Re: Irrational numbers questions
    ... which means what power "a" must I raise the number ... Han de Bruijn ...
    (sci.math)
  • Re: factorial and exponent
    ... It will enable you to do "Arithmetic without Limitations"!! ... Raise A to the power B, storing the result in A. Now raise B to the ...
    (comp.lang.c)
  • Re: HPs mis-calculate fractional exponents?
    ... Nothing at all in the second quadrant, ... I do 5th-root of -2, and then raise that to the fourth power, it works ... This arises because the logarithm is itself ...
    (comp.sys.hp48)
  • Re: SCHIP - is it going to happen this time
    ... his coffee, but he doesn't have the power to force McDonald's ... to raise his salary accordingly. ... Which is paid for by charging more for whatever means the rich ...
    (alt.smokers.cigars)
Quantcast