A Quantum Private Comparison Protocol with Splitting Information Carriers

Abstract

Based on quantum information splitting and reconstruction, we present a quantum private comparison (QPC) protocol, enabling two distrustful parties (Alice and Bob) to compare the equality of their information without revealing the information content. In this protocol, the information carriers are split into two wave packets by a beam splitter (BS), which is owned by a semi-honest third party Trent, and then they are sent to Alice and Bob, respectively. Alice and Bob encodes their secret information on the received wave packets. Only the superimposition of the two wave packets in Trent's site can reveal the compared result. Compared with the QPC protocols using entangled states, the information carriers used in our protocol is single-photon pulse, which reduces the difficulty of realization in practical. In addition, our protocol is feasible with the present techniques since only linear optical components, BS, single-photon detector, phase shifter (PS) and switcher (SWT) are required. The security of the protocol is ensured by principles on the phenomenon of quantum interference. And through the security analysis it shows that the protocol is secure and resists against the well-known attacks.