Quantum Information Processing最新文献

In this work, we investigate two measures of imaginarity: the maximum and minimum relative entropies of imaginarity, and provide their corresponding operational interpretations. For the maximum relative entropy of imaginarity, we demonstrate that it not only characterizes the maximum overlap between a given state and the maximally imaginary state through real operations, but also provides a lower bound for the efficiency of imaginarity distillation. For the minimum relative entropy of imaginarity, we show that it is related to the maximum probability of transformation between pure states using real operations, as well as the minimum time required for a unitary evolution to convert a given pure state into a real state. Furthermore, by introducing the concepts of smooth maximum and minimum relative entropies of imaginarity, as well as the one-shot imaginarity cost and one-shot distillable imaginarity, we establish that the smooth maximum relative entropy of imaginarity provides a lower bound for the one-shot imaginarity cost, while the smooth minimum relative entropy of imaginarity offers an upper bound for the one-shot distillable imaginarity. Finally, we prove that any nontrivial imaginarity measure is not additive under the tensor product of quantum states. Based on this, we prove that the regularized maximum and minimum relative entropies of imaginarity, as well as the regularized relative entropy of imaginarity are all equal to zero for any states, which highlights the distinction between the resource theory of imaginarity and those of entanglement and coherence.

Simon’s algorithm is a well-known quantum algorithm that can achieve exponential acceleration. This paper studies the applications of Simon’s algorithmin analyzing the security of Feistel variants, namely, several well-known cryptographic structures derived from the Feistel structure. Specifically, we study quantum related-key attacks on Feistel variants in the setting that adversaries can only control part of the key difference in quantum superposition. We delve into observing the quantum related-key attacks on the balanced Feistel structure given by Cid et al. and slightly improve the existing method to design periodic functions, ultimately providing a new approach to building periodic functions in single-key settings. Based on these results, we propose a general technique to construct quantum related-key distinguishers exploiting the quantum single-key distinguishers construction technique. As applications of our proposed technique, we demonstrate how to construct new polynomial-time quantum related-key chosen-plaintext distinguishers on several Feistel variants: Feistel-KF, SM4-like, MARS-like, and Type-1/2/3 generalized Feistel-KF structures.

Quantum secret sharing (QSS) harnesses quantum entanglement to securely distribute information among multiple parties, overcoming the vulnerabilities of classical secret sharing schemes, which rely on computational complexity and are susceptible to quantum computing threats. Existing multi-party QSS protocols often exhibit declining efficiency as the number of participants N increases, limiting the scalability. This paper proposes two efficient and verifiable QSS protocols based on a seven-qubit entangled (SQE) state. The first protocol can be extended to multi-party sharing, achieving a sharing efficiency of (3/(2N+2))—a significant improvement over prior schemes. By retaining three particles and distributing the remaining four particles to participants in groups, the protocol enables the reconstruction of three classical secret bits per SQE state, resulting in a particle utilization rate of 75%. Security is ensured through random number generation, local unitary operations, and decoy state technology, which effectively defends against external eavesdropping and internal cheating. Scalable to ((N ge 3)) participants, this protocol reduces the secure multi-party quantum communication cost. The second protocol introduces the random dynamic distribution of particle pairs in three-party secret sharing. Compared to the first protocol, this approach simplifies the verification lists. Moreover, the use of random dynamic particle pair distribution enhances the security of the second protocol.

In this paper, we consider a special class of ((bar{lambda },theta ,ell ))-monomial codes over finite fields, where we describe the Galois duals of one-generator ((bar{lambda },theta ,ell ))-monomial codes generated by a generator of the form ((g(x), g(x)f_1(x), ldots , g(x)f_{ell -1}(x))). We give necessary and sufficient conditions to obtain the Galois self-orthogonality and Galois LCD properties. Furthermore, we construct certain maximum-distance-separable quantum error-correcting codes (MDS QECCs) using the CSS construction from Euclidean and Hermitian self-orthogonal codes. Similarly, we utilize LCD codes to construct certain maximum-distance-separable entanglement-assisted quantum error-correcting codes (MDS EAQECCs).

Quantum robotic systems hold promise for applications in molecular manipulation and high-precision sensing, but their operation is highly vulnerable to environmental noise. This work introduces a large deviation principle (LDP)-based control framework for mitigating stochastic perturbations in coupled master–slave quantum robots. The system Hamiltonian, expressed in terms of position and momentum operators, incorporates control terms alongside Gaussian and Poisson noise, capturing both gradual fluctuations and sudden jumps. By computing the large deviation rate function, we quantify the probability of rare noise-induced deviations and derive an optimal control strategy that minimizes such events in key observables. Simulations across distinct dynamical regimes demonstrate that the controlled trajectories remain close to the desired wave function, with deviations consistent with the theoretical bounds. These results validate the robustness and generality of the approach, providing a practical framework for stabilizing quantum robotic systems in noisy environments with potential applications in precision sensing, molecular chemistry, and quantum computing.

As one of the fundamental quantum circuits widely used today, the quantum modular exponentiation circuit has been applied in various quantum algorithms, including Shor’s algorithm. However, due to the limitations of quantum computers in the noisy intermediate-scale quantum (NISQ) era, excessive circuit depth and high quantum cost can lead to significant noise accumulation, thereby increasing the likelihood of computational errors. Consequently, reducing both circuit depth and quantum cost is essential. To address these issues, this work proposes two modular exponentiation circuits based on the V gate, with further improvements introduced through the use of zero resets. Comparative analysis shows that both proposed circuits achieve reductions in circuit depth and quantum cost within their respective domains, while preserving general applicability. Furthermore, by relaxing the constraint of circuit reversibility, the improved designs achieve an additional two to three fold reduction in circuit depth and quantum cost. Finally, the correctness of the proposed circuits was verified through experimental implementation using the Qiskit package in Python.

The problem of revocation of quantum states after sharing is interesting, and we ask: Is it possible for a dealer to revoke the state once shared, before the reconstruction process? Additional resources like bell states are used to help the dealer to get back the state [1]. In a three-party scenario, we show an independent way to revoke, if, for any reason, the dealer is not sure about the intention of the/any reconstructor. In general, the classical outcomes of the dealer in sharing phase are needed, to be able to reconstruct the state perfectly. When both the shareholders are dishonest^a, and without the dealer’s knowledge, collude to reconstruct, they always have some chance of succeeding. This is addressed by giving more control to the dealer by making him/her to have a quantum share as well. We give a sharing and revocation protocol with a four-qubit entangled resource shared among three parties (two qubits with the dealer and one each with the shareholders). We further consider a class of four-qubit pure entangled states as resource and explicitly find the range of parameters for which the protocol will be successful.

This study explores climate change by predicting methane emissions in North Africa using classical and quantum deep learning methods. Using data from Sentinel-5P, we developed hybrid quantum–classical models, such as quantum long short-term memory (QLSTM) and quantum-gated recurrent unit networks (QGRUs), along with a novel hybrid architecture combining quantum convolutional neural networks (QCNNs) with LSTM and GRU, namely QCNN-LSTM and QCNN-GRU. The results show that these quantum models, especially the proposed hybrid architectures, outperform classical models by approximately seven percent in root-mean-squared error with fewer training epochs. These findings highlight the potential of quantum methodologies for enhancing environmental monitoring accuracy. Future research will aim to refine model performance, incorporate explainable AI techniques, and expand to forecasting other greenhouse gases, contributing to climate change mitigation efforts.

Code-based post-quantum cryptography is seeing an unprecedented growth due to its significance in addressing the security threats posed by quantum computers toward digital communication, leveraging its strength from the well-known hard problems of coding theory. Code-based cryptosystems are vulnerable to attacks that exploit the inherent structure of the underlying code, compromising security in many cases. Although McEliece cryptosystem with Goppa codes provide substantial resistance, this comes at the cost of huge key sizes, limiting their practicality. The proposed work, dynamic code-based McEliece cryptosystem, introduces the notion of dynamicity to the code-based cryptosystem and intensifies the random nature necessary to overcome the attacks. Unlike the conventional schemes that rely on a fixed underlying code and its generator matrix, our approach dynamically changes the code structure in response to trigger events to create cipher keys. This dynamic code transformation preserves the core efficiency of the cipher while significantly improving security against structural attacks, decoding attacks and side channel analysis. The proposed scheme retains IND-CPA security under standard assumptions while also rendering chosen ciphertext attacks significantly challenging. Our work establishes a new direction for enhancing the security of code-based encryption in practical applications.

In recent years, the quantum signature protocol has been an important research topic due to its security against quantum adversaries. Although lots of quantum signature protocols have been presented, their security lacks the support of security model and formal security proof. Especially, their security against adaptively chosen-message attack cannot be proved. Some quantum signature protocols have exposed various security vulnerabilities due to their design defects and informal security analysis. In this paper, based on the single particles, a quantum signature protocol with formal security proof is proposed. In this protocol, the signatory signs the message by cloning the particles and encrypting their states with key-controlled unitary operations. Compared with other similar signature protocols, the advantages of this protocol are as follows: (1) The security of this protocol against forgery attack can be proved with formal security proof under the security model. Its security strictly depends on the principle of quantum unclonability. (2) The security proof need not use the assumption of random oracle. (3) The protocol need not prepare decoy particles for eavesdropping detection, thus saving quantum sources and simplifying the protocol. (4) In the protocol, it is unnecessary to prepare entangled quantum particles. (5) The qubit efficiency reaches 50%, even if the decoy particles are counted.