Quantum Computing.
example the chart below shows a graph of m^j mod n as a function of j when m = 11 and n = 21. Visually you can see that in this case o is equal to 6: Another choice of m, m = 19, is charted here: Those are values of m that happen to be coprime with n, that is gcd(m,n) = 1. If m has a factor in