Quantum Dialogue Based on Non-maximally Entangled Bell States

We propose a new quantum dialogue protocol based on non-maximally entangled Bell states. With single-qubit unitary operation, CNOT gate and the Positive Operator Valued Measure (POVM) technology, a quantum dialogue with certain capacity, can be implemented between two users Alice and Bob. This protocol firstly generalizes the quantum dialogue to a more general scenario which uses non-maximally entangled states as the quantum channel. Security analysis shows that our protocol can resist several well-known security issues. Moreover, it is simple and feasible with current techniques, and it demonstrates a good scalability.