Revisiting the security of quantum dialogue and bidirectional quantum secure direct communication

摘要

From the perspective of information theory and cryptography, we analyze thesecurity of two quantum dialogue protocols and a bidirectional quantum securedirect communication (QSDC) protocol, and point out that the transmittedinformation would be partly leaked out in them. That is, any eavesdropper canelicit some information about the secrets from the public annunciations of thelegal users. This phenomenon should have been strictly forbidden in a quantumsecure communication. In fact, this problem exists in quite a few recentproposals and, therefore, it deserves more research attention in the followingrelated study.