The latter is such that ending the algorithm by an exhaustive search among sequences of limited length is hardly needed. Therefore, the overall complexity of our scheme remains very small, and the algorithm appears as an excellent candidate for cryptanalysis of filtered PN-generators....
As n/δ > 4, Proposition 10 gives that (Π(A)2)2≠ I and (Π(B)2)2)≠ I, so this subgroup is not dihedral, since neither generator has order two. To see that 〈Π(A)2, Π(B)2〉 is not cyclic, suppose, that Π(A)2Π(B)2 = Π(B)2Π(A)2. Then, we know that ...