An Efficient Secure Generalized Comparison Protocol
Motahareh Dehghan, Babak Sadeghiyan · 2018
In this paper, we present a protocol for generalized secure comparison problem. Yao's millionaire problem is for comparing the wealth of two parties by preserving their privacy. If$n$parties want to compare their wealth by using Yao's protocol, it should be run$n(n-1)$2 times; if their wealth interval is as large as N, the complexity of Yao's protocol for$n$parties is in order of N.$\mathbf{n}^{2}, \mathbf{i}.\mathbf{e}$.$\mathbf{O}\ (\mathbf{N}.\mathbf{n}^{2})$. In this paper, we present a generalized secure comparison protocol, which need not to be run by every two parties separately. We use an easy knapsack problem for distinguishing parties' indices. Our protocol computation and communication complexities are bounded by 0 (n).