International Journal of Quantum Information

Physical unclonable functions (PUFs) are physical structures that are hard to clone and have a unique challenge-response behavior. The term PUF was coined by Pappu et al. in 2001. That work triggered a lot of interest, and since then a substantial number of papers has been written about the use of a wide variety of physical structures for different security purposes such as identification, authentication, read-proof key storage, key distribution, tamper evidence, anti-counterfeiting, software-to-hardware binding and trusted computing. In this paper we propose a new security primitive: the quantum-readout PUF (QR-PUF). This is a classical PUF, without internal quantum degrees of freedom, which is challenged using a quantum state, e.g. a single-photon state, and whose response is also a quantum state. By the no-cloning property of unknown quantum states, attackers cannot intercept challenges or responses without noticeably disturbing the readout process. Thus, a verifier who sends quantum states as challenges and receives the correct quantum states back can be certain that he is probing a specific QR-PUF without disturbances, even if the QR-PUF is far away "in the field" and under hostile control. For PUFs whose information content is not exceedingly large, all currently known PUF-based authentication and anti-counterfeiting schemes require trusted readout devices in the field. Our quantum readout scheme has no such requirement. Furthermore, we show how the QR-PUF authentication scheme can be interwoven with quantum key exchange (QKE), leading to an authenticated QKE protocol between two parties. This protocol has the special property that it requires no a priori secret shared by the two parties, and that the quantum channel is the authenticated channel, allowing for an unauthenticated classical channel. We provide security proofs for a limited class of attacks. The proofs depend on the physical unclonability of PUFs and on the practical infeasibility of building a quantum computer.

We propose a continuous variable quantum key distribution protocol based on discrete modulation of eight-state coherent states. We present a rigorous security proof against the collective attacks by taking into consideration the realistic lossy and noisy quantum channel, the imperfect detector efficiency, and the detector electronic noise. This protocol shows high tolerance against excess noise and promises to achieve over 100 km distance of optical fiber.

A family of asymmetric quantum codes derived from the product code of two (classical) Reed–Solomon (RS) codes is constructed in this paper. This family is constructed by applying the Calderbank–Shor–Steane (CSS) construction. The proposed codes can be utilized in quantum channels having great asymmetry, that is, quantum channels in which the probability of occurrence of phase-shift errors is large when compared to the probability of occurrence of qudit-flip errors.

In this paper, we investigate novel protocols for the joint remote state preparation involving several senders and receivers. The highlight of our paper lies in two aspects. First, we focus on the distribution of information among multiple senders and receivers. Second, each receiver can simultaneously reconstruct a qubit state containing the joint information from all senders. These properties imply that our protocols may have many extensive applications in burgeoning quantum network communication. Our protocols cover a variety of class, i.e. two-to-three, N-to-three, and N-to-M. Through introducing the quantum fourier transform, the set of orthogonal basis in the M-dimensional Hilbert space is ingeniously constructed. Moreover, we present all the recovery operations in details. The success probability and the classical communication costs are also given.

In this paper, we investigate the geometric phase of the field interacting with a moving four-level atom in the presence of Kerr medium. The results show that the atomic motion, the field-mode structure and Kerr medium play important roles in the evolution of the system dynamics. As illustration, we examine the behavior of the geometric phase and entanglement with experimentally accessible parameters. Some new aspects are observed and discussed.

A one-way quantum secure direct communication protocol with quantum identification utilizing two-photon three-qubit linear cluster states is proposed. The protocol can be used to transmit a secret message and identify user's identification simultaneously. The transmission of information is instantaneous, i.e. the information can be decoded during the transmission and no final transmission of additional information is needed. We prove its robustness against attacks: Any attempt of an adversary to obtain information (and even a bit of information) necessarily induces some errors that the legitimate parties could notice, even in noisy environments. Moreover, this protocol achieves a high efficiency and source capacity since more qubits can be encoded on the same photon.

We investigate the generation of multipartite entangled SU(k+1) coherent states using a quantum network involving a sequence of k beam splitters. We particularly investigate the entanglement in multipartite SU(2) coherent states (k = 1). We employ the concurrence as measure of the degree of bipartite entanglement.

A typical channel model of the decoherence of qubit is the simultaneous amplitude and phase damping. The parameter region of the channel is classified using the degradability and anti-degradability. It is shown that there is a large parameter region with zero quantum capacity. The formula for one-shot quantum capacity is also given.

In this paper, a new quantum random number generation scheme which is implemented by measuring quantum noise of the squeezed vacuum state is proposed. In the proposed scheme, the Shannon entropy is employed to measure randomness of the generated random numbers. In addition, some characteristics of the generated random numbers are investigated. To reach the pure quantum randomness, an extraction approach based on universal hash functions for the generated quantum random numbers is presented. Results show that the proposed scheme based on squeezed vacuum state has remarkable advantages over the one associated with the vacuum state.

In this paper, we study the teleportation of arbitrary N-qudit state with the tensor representation. The necessary and sufficient condition for realizing a successful or perfect teleportation is obtained, as will be shown, which is determined by the measurement matrix T^δ and the quantum channel parameter matrix X. The general expressions of the measurement matrix T^δ are written out and the quantum channel parameter matrix X are discussed. As an example, we show the details of three-ququart state teleportation.

We introduce joint difference sets as a generalization of cyclic difference sets, and we construct a new class of quantum error-correcting codes (QECCs) from these joint difference sets. The main benefits of our method are as follows. First, we can construct quantum codes that are both high rate and with large block length, while maintaining good performance. Second, the density of constructed quantum parity check matrix can approach zero when the code length is very large. This allows us to use a simple iterative decoding algorithm. Interestingly, our method yields the well-known [5,1,3] QECC.

We introduce a new kind of three-mode coherent-entangled state (CES) |x,β₁,β₂〉, which has both properties of the coherent state and the entangled state. We derive it by virtue of decomposing normally ordered Gaussian operator integrand. An experiment setup to produce the ideal coherent-entangled state is presented. The corresponding Wigner operator and squeezing operator in terms of CES are also given.