It should be a secure two party protocol against malicious adversary.
P1's input is X in Zp* (p is a prime number); P2's input is nothing. P1's output is rX+r'. r,r' are random numbers from Zp* P2' output is r and r'.
Is there any efficent protocol to realize this functionality other than by using homomorphic encrytion? If only HE solves this problem, which is the most efficent one?
Thanks for help!