Question

Find the primitive roots of G=<Z11*, x>?.

(a) {2, 6, 8}

(b) {2, 5, 8}

(c) {3, 4, 7, 8}

(d) {2, 6, 7, 8}

I have been asked this question in quiz.

The origin of the question is Number Theory in chapter More Number Theory of Cryptograph & Network Security

Answer 1

The correct choice is (d) {2, 6, 7, 8}

For explanation I would say: Number of primitive roots = f(f(11))=f((111-110)) = f(10)  = f(2). f(5)

      = (21-20)(51-50) = 1 x 4 = 4

The primitive roots of this set {2, 6, 7, and 8}.