Chung-In Um

A two-receiver quantum dense coding scheme and an $N$-receiver quantum dense coding scheme, in the case of non-symmetric Hilbert spaces of the particles of the quantum channel, are investigated in this paper. A sender can send his messages…

We present a three-party simultaneous quantum secure direct communication (QSDC) scheme by using Greenberger-Horne-Zeilinger (GHZ) states. This scheme can be directly generalized to $N$-party QSDC by using $n$-particle GHZ states. We show…

We present a controlled secure direct communication protocol by using Greenberger-Horne-Zeilinger (GHZ) entangled state via swapping quantum entanglement and local unitary operations. Since messages transferred only by using local…

A controlled quantum dense coding scheme is investigated with a four-particle non-maximal quantum channel. The amount of classical information is shown to be capable of being controlled by the controllers through adjustments of the local…

We propose a scheme for generating entangled states for two superconducting quantum interference devices in a thermal cavity with the assistance of a microwave pulse.

We present a quantum dialogue protocol by using the Greenberger-Horne-Zeilinger (GHZ) state. In this paper, we point out that the `quantum dialogue' communication scheme recently introduced by Nguyen can be eavesdropped on under an…