Paper 3, Section II, G

Number Theory
Part II, 2010

State precisely the Miller-Rabin primality test.

(i) Let pp be a prime 5\geqslant 5, and define

N=4p13N=\frac{4^{p}-1}{3}

Prove that NN is a composite odd integer, and that NN is a pseudo-prime to the base 2 .

(ii) Let MM be an odd integer greater than 1 such that MM is a pseudo-prime to the base 2 . Prove that 2M12^{M}-1 is always a strong pseudo-prime to the base 2 .