A Study of Secure Multi-party Ranking Problem
Wen Liu, Shoushan Luo, Ping Chen · 2007
In this paper, we study a secure multi-party ranking problem: there are n parties, P1, P2, ... , Pn. Each party Pihas a secret input miisin {1, 2, ... ,N}. He wants to get the order of miin the ascending ranking sequence of the n parties' inputs, while not leaking the value of mi. This problem extends the famous Yao's millionaires' problem form two parties to n parties and is a multi-party Yao's Millionaires' problem. We propose a protocol for solving the secure multi-party ranking problem, using the encoding scheme and the El Gamal cryptosystem. We also prove the correctness and the security of our solution in the semi-honest model. The solution of secure multi-party ranking problem can make new-style electronic transactions, such as private bidding and auction, secret online transaction and so on, become better security.