arXiv subjects

Nilesh Vyas

Publications and source records attributed to Nilesh Vyas.

11 recordsLinked to original sources

arXiv2026

Homomorphic Aggregation of Continuous-Variable GKP States

Aggregating logical information in continuous-variable quantum networks is essential for distributed quantum architecture. However, direct passive linear optics degrade non-Gaussian Gottesman-Kitaev-Preskill (GKP) grid states via symplectic lattice compression and entanglement-induced decoherence when auxiliary modes are discarded. We present an active, measurement-based continuous-variable network primitive for combining spatially distributed computational-basis payloads. Utilizing GKP Bell states, homodyne measurements, and conditional feed-forward phase-space displacements, we construct a completely positive trace-preserving (CPTP) map that evaluates a logical XOR operation on computational-basis inputs. We bound the Heisenberg action of the physical finite-squeezing channel on logical Pauli generators, demonstrate measurement-specific homodyne-outcome hiding for continuous-variable quantum one-time pads (CV-OTP) with an explicit prefactor bound $D_{\mathrm{TV}} \le 1.60 e^{-r}$, and evaluate logical success probabilities under physical optical loss and network scaling constraints.

quant-ph↗

arXiv2026

Feasibility of satellite-augmented global quantum repeater networks

A large scale quantum network requires the distribution of high-fidelity end-to-end entanglement. To overcome the range limitations inherent to terrestrial fiber, a leading architecture has emerged: satellite-based sources transmitting entanglement to quantum repeaters on the ground. By bridging the gap between abstract analytical frameworks and computationally heavy numerical simulations, this paper provides the first quantitative answer to the question of such a network's achievable performance with current and near-term space technology, while accounting for entanglement swapping and purification. This is achieved by integrating a detailed physical model of a satellite-to-ground link into an analytical entanglement resource estimation framework for quantum repeaters, enabling an optimization of the end-to-end entanglement rate. Our analysis, performed across leading quantum hardware platforms, shows that Low Earth Orbit satellite constellations combined with quantum repeaters employing Neutral Atom or Nitrogen and Silicon Vacancy qubits, could enable a global quantum network, distributing entanglement over distances up to 20,000 km, sufficient for connecting any two points on Earth. This work highlights the major bottlenecks in space and quantum hardware technologies, which need to be addressed, thereby guiding informed investments necessary for enabling a large scale quantum network.

quant-ph↗

arXiv2026

Reliable and Private Anonymous Routing for Satellite Constellations

Shared, dynamic network infrastructures, such as dual-use LEO satellite constellations, pose critical threats to metadata privacy, particularly for state actors operating in mixed-trust environments. This work proposes an enhanced anonymity architecture, evolving the Loopix mix-network, to provide robust security and reliability in these volatile topologies. We introduce three primary contributions: (1) A multi-path transport protocol utilizing $(n, k)$ erasure codes, which is demonstrated to counteract the high link volatility and intermittent connectivity that renders standard mix-networks unreliable. (2) The integration of a computationally efficient Private Information Retrieval (PIR) protocol during route discovery. (3) The introduction of adaptive, centrality-based delay strategies that efficiently mitigate the inherent topological bias of LEO networks, providing a superior anonymity-to-latency trade-off. This mechanism provably prevents metadata leakage at the user-provider directory, mitigating profiling and correlation attacks. We validate this architecture via high-fidelity, packet-level simulations of a LEO constellation. Empirical results show our multi-path transport achieves near-zero message loss, establishing a quantifiable trade-off between reliability and bandwidth overhead. Furthermore, microbenchmarks of the PIR protocol quantify its computational and latency overheads, confirming its feasibility for practical deployment. This work provides a validated blueprint for deployable high-anonymity communication systems, demonstrating the viability of securely multiplexing sensitive operations within large-scale commercial network infrastructures.

cs.CR↗

arXiv2025

QADR: A Scalable, Quantum-Resistant Protocol for Anonymous Data Reporting

The security of future large-scale IoT networks is critically threatened by the ``Harvest Now, Decrypt Later'' (HNDL) attack paradigm. Securing the massive, long-lived data streams from these systems requires protocols that are both quantum-resistant and highly scalable. Existing solutions are insufficient: post-quantum classical protocols rely on computational assumptions that may not hold for decades, while purely quantum protocols are too resource-intensive for the sheer scale of IoT. This paper introduces the Quantum Anonymous Data Reporting (QADR) protocol, a hybrid framework that provides a theoretical benchmark and high-performance architecture for this challenge, designed for future fully-connected quantum networks. The protocol achieves scalable, quantum-resistant anonymity through a hybrid security model; it leverages information-theoretically secure keys from Quantum Key Distribution (QKD) to seed a quantum-secure pseudorandom function (QS-PRF), grounding its long-term data protection in well-established computational hardness assumptions. We also propose and analyze an automated slot reservation mechanism by making a deliberate trade-off: achieving high performance by accepting a quantifiable information leak during the anonymous slot reservation phase while maintaining strong unlinkability for the final data submission. Our security analysis formally quantifies the anonymity reduction caused by the leak and discusses pathways to fully mitigate it at a significant performance cost. We prove the protocol's critical advantage as a performance benchmark: its primary communication cost scales as $O(n^2)$, a dramatic improvement over quantum-native alternatives ($O(n^4)$), establishing a high-performance goal for future quantum-secured anonymity systems.

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arXiv2025

Privacy-Preserving IoT in Connected Aircraft Cabin

The proliferation of IoT devices in shared, multi-vendor environments like the modern aircraft cabin creates a fundamental conflict between the promise of data collaboration and the risks to passenger privacy, vendor intellectual property (IP), and regulatory compliance. While emerging standards like the Cabin Secure Media-Independent Messaging (CSMIM) protocol provide a secure communication backbone, they do not resolve data governance challenges at the application layer, leaving a privacy gap that impedes trust. This paper proposes and evaluates a framework that closes this gap by integrating a configurable layer of Privacy-Enhancing Technologies (PETs) atop a CSMIM-like architecture. We conduct a rigorous, empirical analysis of two pragmatic PETs: Differential Privacy (DP) for statistical sharing, and an additive secret sharing scheme (ASS) for data obfuscation. Using a high-fidelity testbed with resource-constrained hardware, we quantify the trade-offs between data privacy, utility, and computing performance. Our results demonstrate that the computational overhead of PETs is often negligible compared to inherent network and protocol latencies. We prove that architectural choices, such as on-device versus virtualized processing, have a far greater impact on end-to-end latency and computational performance than the PETs themselves. The findings provide a practical roadmap for system architects to select and configure appropriate PETs, enabling the design of trustworthy collaborative IoT ecosystems in avionics and other critical domains.

cs.CR↗

arXiv2025

Quantum Internet: Resource Estimation for Entanglement Routing

Quantum repeaters have promised efficient scaling of quantum networks for over two decades. Despite numerous platforms proclaiming functional repeaters, the realization of large-scale networks remains elusive, indicating that the resources required to do so were thus far underestimated. Here, we investigate the dependence of resource scaling of networks on realistic experimental errors. Using a nested repeater protocol based on the purification protocol by Bennett et. al., we provide an analytical approximation of the polynomial degree of the resources consumed by entanglement routing. Our error model predicts substantially stricter thresholds for efficient network operation than previously suggested, requiring two-qubit gate errors below 1.3% for resource scaling with polynomial degree below 10. The analytical model presented here provides insight into the reason why previous experimental implementations of quantum repeaters failed to scale efficiently and inform the development of truly scalable systems, highlighting the need for high-fidelity local two-qubit gates. We employ our analytical approximation of the scaling exponent as a figure of merit to compare different platforms and find that trapped ions and color centers in diamond currently provide the best route towards large-scale networks.

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arXiv2025

Feasibility of Logical Bell State Generation in Memory Assisted Quantum Networks

This study explores the feasibility of utilizing quantum error correction (QEC) to generate and store logical Bell states in heralded quantum entanglement protocols, crucial for quantum repeater networks. Two lattice surgery-based protocols (local and non-local) are introduced to establish logical Bell states between distant nodes using an intermediary node. We simulate the protocols using realistic experimental parameters, including ion trap memories, noisy optical channels, frequency conversion, and non-destructive detection of photonic qubits. The study evaluates rotated and planar surface codes alongside Bacon-Shor codes for small code distances ($d = 3, 5$) under depolarizing and physical noise models. Pseudo-thresholds are identified, with physical error rates above $p_{\text{err}} \sim 10^{-3}$ offering no advantage over unencoded Bell states under depolarizing noise. Pseudo-thresholds are also reevaluated in terms of gate error rates $p_{\text{err}_H}$, $p_{\text{err}_{CX}}$, and $p_{\text{err}_M}$. For a distance of 1 km between the end node and the intermediary, an advantage over unencoded Bell-state heralded protocols requires reducing gate error rates by an order of magnitude ($0.1p_{\text{err}_H}$, $0.1p_{\text{err}_{CX}}$, and $0.1p_{\text{err}_M}$). These results highlight the need for significant hardware improvements to implement logical Bell state protocols with quantum memories. Additionally, the non-local protocol rate was analyzed, achieving rates up to $(32.53 \pm 1.53) \, \mathrm{Hz}$ over distances of $1$ to $80 \, \mathrm{km}$ between the end node and the intermediary node.

quant-ph↗

arXiv2024

Relaxing Trust Assumptions on Quantum Key Distribution Networks

Quantum security over long distances with untrusted relays is largely unfounded and is still an open question for active research. Nevertheless, quantum networks based on trusted relays are being built across the globe. However, standard QKD network architecture implores a complete trust requirement on QKD relays, which is too demanding and limits the use cases for QKD networks. In this work, we explore the possibility to securely relay a secret in a QKD network by relaxing the trust assumptions (if not completely) on the relay. We characterize QKD relays with different trust levels, namely, Full Access Trust (FAT), Partial Access Trust (PAT), and No Access Trust (NAT). As the name suggests, each level defines the degree with which a relay is required to be trusted with the secret provided by the key management system for end-to-end communication. We then review and propose multiple constructions of the QKD key management system based on the different trust levels. Main contribution of the paper is realized by evaluating key management systems with no access trust level. In principle, we review key management with centralized topology and propose a new decentralized key management system. These different topologies provide various advantages based on the QKD network requirements, allowing an operational flexibility in the architecture. We believe this work presents a new perspective to the open problem of providing a confiding and a practical solution for future long range secure communications

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arXiv2021

Is the essence of a quantum game captured completely in the original classical game?

S. J. van Enk and R. Pike in PRA 66, 024306 (2002) argue that the equilibrium solution to a quantum game isn't unique but is already present in the classical game itself. In this work, we contest this assertion by showing that a random strategy in a particular quantum (Hawk-Dove) game is unique to the quantum game. In other words, one cannot obtain the equilibrium solution of the quantum Hawk-Dove game in the classical Hawk-Dove game. Moreover, we provide an analytical solution to the quantum $2\times2$ strategic form Hawk-Dove game using randomly mixed strategies. The random strategy which we describe is Pareto optimal with their payoff classically unobtainable. We compare quantum strategies to correlated strategies and find that correlated strategies in the quantum Hawk-Dove game or quantum Prisoner's dilemma yield the Nash equilibrium solution.

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arXiv2020

Everlasting Secure Key Agreement with performance beyond QKD in a Quantum Computational Hybrid security model

Extending the functionality and overcoming the performance limitation under which QKD can operate requires either quantum repeaters or new security models. Investigating the latter option, we introduce the \textit{Quantum Computational Hybrid} (QCH) security model, where we assume that computationally secure encryption may only be broken after time much longer than the coherence time of available quantum memories. We propose an explicit $d$-dimensional key distribution protocol, that we call MUB-\textit{Quantum Computational Timelock} (MUB-QCT) where one bit is encoded on a qudit state chosen among $d+1$ mutually unbiased bases (MUBs). Short-term-secure encryption is used to share the basis information with legitimate users while keeping it unknown from Eve until after her quantum memory decoheres. This allows reducing Eve's optimal attack to an immediate measurement followed by post-measurement decoding. \par We demonstrate that MUB-QCT enables everlasting secure key distribution with input states containing up to $O(\sqrt{d})$ photons. This leads to a series of important improvements when compared to QKD: on the functional side, the ability to operate securely between one sender and many receivers, whose implementation can moreover be untrusted; significant performance increase, characterized by a $O(\sqrt{d})$ multiplication of key rates and an extension by $25 {\rm} km \times \log(d)$ of the attainable distance over fiber. Implementable with a large number of modes with current or near-term multimode photonics technologies, the MUB-QCT construction has the potential to provide a radical shift to the performance and practicality of quantum key distribution.

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arXiv2015

Rooted-tree network for optimal non-local gate implementation

A general quantum network for implementing non-local control-unitary gates, between remote parties at minimal entanglement cost, is shown to be a rooted-tree structure. Starting from a five party scenario, we demonstrate the local implementation of simultaneous control-Hermitian and multiparty control-unitary gates in an arbitrary n-party network. Previously established networks are shown to be special cases of this general construct.

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