Narrow Results

A quantum authentication scheme is presented in this paper. Two parties share Einstein-Podolsky-Rosen(EPR) pairs previously as the identification token. They create auxiliary EPR pairs to interact with the identification token. Then the authentication is accomplished by a complete Bell state measurement. This scheme is proved to be secure. If no errors and eavesdroppers exist in the transmission, the identification token is unchanged after the authentication. So it can be reused.

An efficient three-party quantum secret sharing scheme is proposed. The dealer uses the phase shift operation to encode the secret information into some EPR pairs. The members use the phase shift operation to decode the EPR pairs, and measure the EPR pairs to reconstruct the secret. Our scheme does not need the BB84 protocol or the decoy particles to protect the transmitted particles, and can use the phase shift operation to prevent the attacker from stealing secret information from the transmitted particles. So all the particles can be used to bring the secret information, and the utilization efficiency of the particles of 100% can be achieved. With the prevent technology, our scheme is more practical than the existing schemes.

We present a scheme of remote preparation of the two-particle state by using two Einstein–Podolsky–Rosen pairs or two partially entangled two-particle states as the quantum channel. The probability of the successful remote state preparation is obtained.

In this paper, we revisit the entanglement concentration protocol of Bennett et al. and the entanglement dilution protocol of Lo and Popescu via the method of types and provide a simple upper bound on the coefficient of the bound on the classical communication cost of the Lo-Popescu protocol.

This paper offers a theoretical protocol for one-party controlled remote state preparation (RSP) of n-qubit states with minimum resources consumption. We are mainly focused on the case of the n-qubit state chosen from equatorial circle on a Bloch sphere. We use n - 1 EPR pairs and one GHZ state as quantum channel and show that only n + 1 cbits, n ebits and 2n + 1 qubits are consumed during the controlled RSP processing.

In the 1920s when quantum mechanics was being established, there was a famous controversy between Bohr and Einstein about the statistical interpretation of quantum mechanics. The controversy was finally concluded by an emphatic victory of Bohr, since his statistical interpretation and the duality of wave and particle explained many experimental facts without any difficulty. The “Gedanken” experiment on two entangled particles (the EPR pair) presented by Einstein, Podolski and Rosen in the course of the controversy, however, has had a continuous influence for many years on quantum communication and quantum cryptography which are being developed at the present day.

The following sections are included:

• EPR pair

• Transmission of quantum states

• Einstein's locality principle in quantum mechanics

• Measurement of two correlated particles and hidden variable theorem
  • CHSH inequality
  • Classical correlation vs. quantal correlation: a case of nuclear fission

• EPR experiment by photon pairs

• Four-photon GHZ states

• Problems