Fair and efficient protocol for secure two-party comparing under semi-honest model
Liang Chen, Gao Cheng-min · Computer Engineering and Applications Journal · 2010
The essential of Yao’s millionaire problem is securely comparing two numbers,which is a basic building block of secure computations and has many important applications in e-commerce,such as bidding,auction and so on.But known solutions have some disadvantagesf,or example expensive costs of computing and communicatingl,imited ranges of compared numbers.This paper proposes a modified ElGamal algorithm,based on which multiplicative and subtractive homomorphic cryp-tosystem is presented and proved.Based on the homomorphic cryptosystem,Fair and Efficient Protocol for Secure Two-party Comparing(FEPSTC) under semi-honest model is constructed.The main properties of the FEPSTC are securityf,airnessl,ower costs of communication and computational complexity,and comparing real numbers.They are proved and illustrated by an ex-ample and by comparing with other protocols.