Euler's Totient Theorem - CMU
math.cmu.edu › 12-13 › number-theory-11/11/12Nov 11, 2012 · Euler’s Theorem Theorem If a and n have no common divisors, then a˚(n) 1 (mod n) where ˚(n) is the number of integers in f1;2;:::;ngthat have no common divisors with n. So to compute ab mod n, rst nd ˚(n), then calculate c = b mod ˚(n). Then all you need to do is compute ac mod n.