Improving the security of secure deterministic communication scheme based on quantum remote state preparation

The security of the quantum secure deterministic communication scheme Chin. Phys. 16 (2007) 2549 is reexamined. A security loophole is pointed out. Taking advantage of this loophole, an eavesdropper can steal all the secret messages without being detected by an intercept-and-resend attack strategy. Furthermore, a possible improvement on this protocol is presented. It makes the modified protocol secure against this kind of attack.