Quantum secure conditional direct communication via EPR pairs

In this letter a deterministic secure direct bidirectional communication protocol is proposed by using the quantum entanglement and local unitary operations on one photon of the Einstein-Podolsky-Rosen (EPR) photon pair.

A novel communication protocol based on an entangled pair of qubits is presented, allowing secure direct communication from one party to another without the need for a shared secret key. Since the information is transferred in a deterministic manner, no qubits have to be discarded and every qubit carries message information. The security of the transfer against active and passive eavesdropping attacks is provided. The detection rate of active attacks is at least 25%. The prot...

Recently, Boyer et al. presented a novel semiquantum key distribution protocol [M. Boyer, D. Kenigsberg, and T. Mor, Phys. Rev. Lett. 99, 140501 (2007)], in which quantum Alice shares a secret key with classical Bob. Li et al. proposed two semiquantum secret sharing protocols [Q. Li, W. H. Chan, and D. Y. Long, Phys. Rev. A 82, 022303 (2010)] by using maximally entangled Greenberger-Horne-Zeilinger states. In this paper, we present a semiquantum secret sharing protocol by usi...

An efficient quantum secret sharing scheme is proposed. In this scheme, the particles in an entangled pair group form two particle sequences. One sequence is sent to Bob and the other is sent to Charlie after rearranging the particle orders. Bob and Charlie make coding unitary operations and send the particles back. Alice makes Bell-basis measurement to read their coding operations.

A novel secure communication protocol is presented, based on an entangled pair of qubits and allowing asymptotically secure key distribution and quasi-secure direct communication. Since the information is transferred in a deterministic manner, no qubits have to be discarded. The transmission of information is instantaneous, i.e. the information can be decoded during the transmission. The security against arbitrary eavesdropping attacks is provided. In case of eavesdropping at...

We present a deterministic secure direct communication scheme via entanglement swapping, where a set of ordered maximally entangled three-particle states (GHZ states), initially shared by three spatially separated parties, Alice, Bob and Charlie, functions as a quantum information channel. After ensuring the safety of the quantum channel, Alice and Bob apply a series local operations on their respective particles according to the tripartite stipulation and the secret message ...

We present an one-time-pad key communication protocol that allows secure direct communication with entanglement. Alice can send message to Bob in a deterministic manner by using local measurements and public communication. The theoretical efficiency of this protocol is double compared with BB84 protocol. We show this protocol is unconditional secure under arbitrary quantum attack. And we discuss that this protocol can be perfectly implemented with current technologies.

A theoretical scheme for controlled and secure direct communication is proposed. The communication is based on GHZ state and controlled quantum teleportation. After insuring the security of the quantum channel (a set of qubits in the GHZ state), Alice encodes the secret message directly on a sequence of particle states and transmits them to Bob supervised by Charlie using controlled quantum teleportation. Bob can read out the encoded messages directly by the measurement on hi...

Most of the quantum secure direct communication protocol needs a pre-established secure quantum channel. Only after insuring the security of quantum channel, could the sender encode the secret message and send them to the receiver through the secure channel. In this paper, we present a quantum secure direct communication protocol using Einstein-Podolsky-Rosen pairs. It is not necessary for the present protocol to insure the security of quantum channel before transmitting the ...

We present a quantum secure direct communication protocol and a multiparty quantum secret sharing protocol based on Einstein-Podolsky-Rosen pairs and entanglement swapping. The present quantum secure direct communication protocol makes use of the ideal of block transmission. We also point out that the sender can encode his or her secret message without ensuring the security of the quantum channel firstly. In the multiparty quantum secret sharing protocol, the communication pa...