as the identity information of the prover. Note
that xk is obtained by k many applications of h to x0:
xn+1 = h(xn)
h(x) = xe mod n
is essentially the RSA-based hash function discussed already in class. The authority is responsible for computing p and q and it keeps those parameters secret. The provers and verifiers will obtain n and e so that they are able to compute h. Since the authority knows the factorization of n, it can easily derive an efficient algorithm for computing inverses of h. That way, it can investigate and rule disputes between provers and verifiers.
Feel free to consult me during my Office Hours: W 2:00--3:00 P.M., U 10:30--11:30 A.M.
Michael Huth (huth@cis.ksu.edu)