Related papers: A fundamental threat to quantum cryptography: grav…

This paper consists of musings that originate mainly from conversations with other physicists, as together we've tried to learn some cryptography, but also from conversations with a couple of classical cryptographers. The main thrust of the…

Quantum key distribution algorithms are considered secure because they leverage quantum phenomena to provide security. As such, eavesdroppers can be detected by analyzing the error rate in the shared key obtained by the parties performing…

B92-type and BB84-type quantum cryptography schemes using superposed states of the vacuum and single particle states which are robust against PNS attacks are studied. The number of securely transferred classical bits per particle (not per…

Practical quantum key distribution (QKD) systems operate under noise, but security of most protocols have been analyzed under ideal noiseless scenarios. In this work, we investigated security performance of BB84 protocol under effect of…

We study quantum secure direct communication by using a general preshared quantum state and a generalization of dense coding. In this scenario, Alice is allowed to apply a unitary on the preshared state to encode her message, and the set of…

A quantum key distribution protocol based on quantum encryption is presented in this Brief Report. In this protocol, the previously shared Einstein-Podolsky-Rosen pairs act as the quantum key to encode and decode the classical cryptography…

Unconditional security proofs of the Bennett-Brassard protocol of quantum key distribution have been obtained recently. These proofs cover also practical implementations that utilize weak coherent pulses in the four signal polarizations.…

Quantum states cannot be cloned. I show how to extend this property to classical messages encoded using quantum states, a task I call "uncloneable encryption." An uncloneable encryption scheme has the property that an eavesdropper Eve not…

Secure key distribution among two remote parties is impossible when both are classical, unless some unproven (and arguably unrealistic) computation-complexity assumptions are made, such as the difficulty of factorizing large numbers. On the…

As a new model for signing quantum message, arbitrated quantum signature (AQS) has recently received a lot of attention. In this paper we study the cryptanalysis of previous AQS protocols from the aspects of forgery and disavowal. We show…

Nowadays security in communication is increasingly important to the network communication because many categories of data are required restriction on authorization of access, modify, delete and insert. Quantum cryptography is one of the…

A quantum cryptographic protocol based in public key cryptography combinations and private key cryptography is presented. Unlike the BB84 protocol [1] and its many variants [2,3] two quantum channels are used. The present research does not…

Unconditionally secure non-relativistic bit commitment is known to be impossible in both the classical and the quantum world. However, when committing to a string of n bits at once, how far can we stretch the quantum limits? In this letter,…

A user, Alice, wants to get server Bob to implement a quantum computation for her. However, she wants to leave him blind to what she's doing. What are the minimal communication resources Alice must use in order to achieve…

In this paper, security of practically decoy state quantum key distribution under fake state attack is considered. If quantum key distribution is insecure under this type of attack, decoy sources can not also provide it with enough…

Private queries allow a user Alice to learn an element of a database held by a provider Bob without revealing which element she was interested in, while limiting her information about the other elements. We propose to implement private…

In a deterministic quantum key distribution (DQKD) protocol with a two-way quantum channel, Bob sends a qubit to Alice who then encodes a key bit onto the qubit and sends it back to Bob. After measuring the returned qubit, Bob can obtain…

With the emergence of an information society, the idea of protecting sensitive data is steadily gaining importance. Conventional encryption methods may not be sufficient to guarantee data protection in the future. Quantum key distribution…

Quantum Key Distribution is a quantum communication technique in which random numbers are encoded on quantum systems, usually photons, and sent from one party, Alice, to another, Bob. Using the data sent via the quantum signals,…

In a recent paper [S. Bagherinezhad and V. Karimipour, Phys. Rev. A 67, 044302 (2003)], a quantum secret sharing protocol based on reusable GHZ states was proposed. However, in this Comment, it is shown that this protocol is insecure if Eve…