Abstract:

In quantum cryptography, it is commonly established that quantum key distribution and quantum secure direct communication work in a single direction, namely one direction communication schemes. However, quantum dialog protocol can enable two legal users exchange messages simultaneously, namely two direction communication. most existed proposals of quantum dialog protocol are based on discrete variables, which are much more difficult to implement with today’s technology, thus they are less practical than its counterpart. Based on squeezed states, we propose a new quantum dialog scheme, information-theoretical analysis is then followed and shows that our scheme is not only secure, but also has larger channel capacity than that of its counterpart.

Key words: quantum information, quantum cryptography, continuous variable, quantum dialogue