Secure communication has achieved a new dimension with the advent of the schemes of
quantum key distribution (QKD) as in contrast with classical cryptography, quantum …

This introductory textbook is written primarily for undergraduate students of physics,
mathematics, computer science and other related disciplines. It is also expected to be …

To achieve unconditional security through quantum key distribution (QKD), users involved in
key distribution first need to authenticate each other. Classical identity authentication …

Semi-quantum protocols that allow some of the users to remain classical are proposed for a
large class of problems associated with secure communication and secure multiparty …

We briefly review the ideas that have shaped modern optics and have led to various
applications of light ranging from spectroscopy to astrophysics, and street lights to quantum …

Two protocols of quantum key agreement (QKA) that solely use Bell state and Bell
measurement are proposed. The first protocol of QKA proposed here is designed for two …

Private comparison is a primitive for many cryptographic tasks, and recently several
schemes for the quantum private comparison (QPC) have been proposed, where two users …

A new two-party quantum key agreement (QKA) protocol is proposed based on four-qubit
cluster states. Encoded four-qubit cluster states can be transmitted directly by means of …

Based on unitary operations and four-qubit cluster states, a two-party and a three-party
quantum key agreement protocols are proposed, respectively, in this paper. The two-party …

Based on four-qubit cluster states, we present a two-party quantum key agreement (QKA)
scheme using unitary operations. In this scheme, two participants perform the unitary …