The Security Analysis Of Quantum Cryptography Protocols

Quantum cryptographic protocol is essentially a cryptographic protocol based on quantummechanics. The security of quantum cryptographic protocol is a very important research field.In this paper, we analyze the security of three quantum cryptographic protocols, in whichone is a threshold proxy quantum signature protocol, the other two are quantum secret sharingprotocols. The main research results are listed as follows.1. This paper analyzes the security of the YGL quantum secret sharing protocol betweenmultiparty and multiparty with four quantum states, which was proposed by Yan et al.. We showthat the protocol is not secure because one dishonest participant, for example, the last member inAlices group, with a special attack strategy, can illegally extract the secret messages shared bytwo legitimate groups without introducing any errors. Moreover, an external attacker can alsoobtain the secret message shared by the two groups. This is because the messages, which aretransmitted on the quantum and classical channels, are not protected by message authentication.These results show that there are some hidden security loopholes in this quantum secret sharingprotocol.2. This paper analyzes the security of the LS quantum secret sharing protocol withcollective eavesdropping-check, which was proposed by Lin Song et al.. We show that theprotocol is not secure because the last participant, with a special attack strategy, can illegallyextract the secret messages shared by two all member without introducing any errors. Thisresult shows that there are some hidden security loopholes in this quantum secret sharingprotocol.3. This paper analyzes the security of the YW threshold proxy quantum signature scheme,YW-scheme, which was proposed by Yang YuGuang and Wen QiaoYan. In this signature scheme,it is found that the basic signature key is the same as the basic verification key, which means thatthe bitwise exclusive OR (XOR) of the t proxy signature keys is exactly the XOR of the t proxyverification keys. Therefore, the proxy signers can deny their signature and the specific verifierscan forge a legal signature. Furthermore, an attacker can obtain a legal threshold proxy signaturefor an arbitrary new message. These findings show that there are hidden security loopholes thatshould be carefully fixed in designing more efficient YW-scheme.