Navigation College, Jimei University, Xiamen, 361021, China.
School of Computer Science and Engineering, Southeast University, Nanjing, 211189, China.
Key Laboratory of Computer Network and Information Integration, Southeast University, Ministry of Education, Nanjing, 211189, China.
Institute for Quantum Computing, University of Waterloo, Waterloo, ON, Canada, N2L3G1.
Abstract:
The controlled quantum secure direct communication (CQSDC) with authentication protocol based on four particle cluster states via quantum one-time pad and local unitary operations is cryptanalyzed. It is found that there are some serious security issues in this protocol. An eavesdropper (Eve) can eavesdrop on some information of the identity strings of the receiver and the controller without being detected by the selective-CNOT-operation (SCNO) attack. By the same attack, Eve can also steal some information of the secret message that the sender transmits. In addition, the receiver can take the same kind of attack to eavesdrop on some information of the secret message out of the control of the controller. This means that the requirements of CQSDC are not satisfied. At last, we improve the original CQSDC protocol to a secure one.
