Valerio Scarani , Helle Bechmann-Pasquinucci , Nicolas J. Cerf , Miloslav DuÅ¡ek , Norbert LÃ¼tkenhaus , Momtchil Peev 9 1 Centre for Quantum Technologies and Department of Physics, National Universityâ€¦ (More)

All incoherent as well as 2and 3-qubit coherent eavesdropping strategies on the 6 state protocol of quantum cryptography are classified. For a disturbance of 1/6, the optimal incoherent eavesdroppingâ€¦ (More)

We consider quantum cryptographic schemes where the carriers of information are 3-state particles. One protocol uses four mutually unbiased bases and appears to provide better security thanâ€¦ (More)

Like all of quantum information theory, quantum cryptography is traditionally based on two level quantum systems. In this letter, a new protocol for quantum key distribution based on higherâ€¦ (More)

A trusted quantum relay is introduced to enable quantum key distribution links to form the basic legs in a quantum key distribution network. The idea is based on the well-known intercept/resendâ€¦ (More)

First, we present a Bell-type inequality for n qubits, assuming that m out of the n qubits are independent. Quantum mechanics violates this inequality by a ratio that increases exponentially with m.â€¦ (More)

In this paper quantum seals will be introduced. A quantum seal is a way of encoding a classical message into quantum states, so that everybody can read the message error-free, but at the same timeâ€¦ (More)

Sealing information means making it publicly available, but with the possibility of knowing if it has been read. Commenting on [1], we will show that perfect quantum sealing is not possible forâ€¦ (More)

Quantum state targeting is a quantum game which results from combining traditional quantum state estimation with additional classical information. We consider a particular version of the game andâ€¦ (More)

In quantum cryptography the optimal eavesdropping strategy requires that the eavesdropper uses quantum memories in order to optimize her information. What happens if the eavesdropper has no quantumâ€¦ (More)