I'm working on a RSA assignment. Since the numbers were getting pretty large is used the InfInt biginter library. Now, the problem I'm facing is, if the numbers are too big like 6-7 digit input, the exponention function is taking too much time.
InfInt modPow(InfInt base, InfInt exp, InfInt n)
{
base = base%n;
if (exp == 0)
return 1;
else if (exp == 1)
return base;
else if (exp%2 == 0)
return modPow(base*base%n, exp/2, n);
else
return base*modPow(base, exp-1, n)%n;
}
Is there anyway, I can increase the speed ? I have read the Euler's method and others, but can't understand much. Will be great if someone can explain how to quicken this function.
Thanks
