ترغب بنشر مسار تعليمي؟ اضغط هنا

Forging quantum data: classically defeating an IQP-based quantum test

62   0   0.0 ( 0 )
 نشر من قبل Gregory D. Kahanamoku-Meyer
 تاريخ النشر 2019
والبحث باللغة English




اسأل ChatGPT حول البحث

In 2009, Shepherd and Bremner proposed a test of quantum capability arXiv:0809.0847 that is attractive because the quantum machines output can be verified efficiently by classical means. While follow-up papers gave evidence that directly simulating the quantum prover is classically hard, the security of the protocol against other (non-simulating) classical attacks has remained an open question. In this paper, I demonstrate that the protocol is not secure against classical provers. I describe a classical algorithm that can not only convince the verifier that the (classical) prover is quantum, but can in fact can extract the secret key underlying a given protocol instance. Furthermore, I show that the algorithm is efficient in practice for problem sizes of hundreds of qubits. Finally, I provide an implementation of the algorithm, and give the secret vector underlying the $25 challenge posted online by the authors of the original paper.



قيم البحث

اقرأ أيضاً

We propose and analyze a novel interactive protocol for demonstrating quantum computational advantage, which is efficiently classically verifiable. Our protocol relies upon the cryptographic hardness of trapdoor claw-free functions (TCFs). Through a surprising connection to Bells inequality, our protocol avoids the need for an adaptive hardcore bit, with essentially no increase in the quantum circuit complexity and no extra cryptographic assumptions. Crucially, this expands the set of compatible TCFs, and we propose two new constructions: one based upon the decisional Diffie-Hellman problem and the other based upon Rabins function, $x^2 bmod N$. We also describe two unique features of our interactive protocol: (i) it allows one to discard so-called garbage bits, thereby removing the need for reversibility in the quantum circuits, and (ii) there exists a natural post-selection scheme, which significantly reduces the fidelity needed to demonstrate quantum advantage. Finally, we design several efficient circuits for $x^2 bmod N$ and describe a blueprint for their implementation on a Rydberg-atom-based quantum computer.
Quantum computers are promising for simulations of chemical and physical systems, but the limited capabilities of todays quantum processors permit only small, and often approximate, simulations. Here we present a method, classical entanglement forgin g, that harnesses classical resources to capture quantum correlations and double the size of the system that can be simulated on quantum hardware. Shifting some of the computation to classical post-processing allows us to represent ten spin-orbitals on five qubits of an IBM Quantum processor to compute the ground state energy of the water molecule in the most accurate simulation to date. We discuss conditions for applicability of classical entanglement forging and present a roadmap for scaling to larger problems.
Privacy amplification (PA) is an essential part in a quantum key distribution (QKD) system, distilling a highly secure key from a partially secure string by public negotiation between two parties. The optimization objectives of privacy amplification for QKD are large block size, high throughput and low cost. For the global optimization of these objectives, a novel privacy amplification algorithm is proposed in this paper by combining multilinear-modular-hashing and modular arithmetic hashing. This paper proves the security of this hybrid hashing PA algorithm within the framework of both information theory and composition security theory. A scheme based on this algorithm is implemented and evaluated on a CPU platform. The results on a typical CV-QKD system indicate that the throughput of this scheme ([email protected]*10^8 input block size) is twice higher than the best existing scheme (140Mbps@1*10^8 input block size). Moreover, This scheme is implemented on a mobile CPU platform instead of a desktop CPU or a server CPU, which means that this algorithm has a better performance with a much lower cost and power consumption.
Inferring causal relations from experimental observations is of primal importance in science. Instrumental tests provide an essential tool for that aim, as they allow one to estimate causal dependencies even in the presence of unobserved common cause s. In view of Bells theorem, which implies that quantum mechanics is incompatible with our most basic notions of causality, it is of utmost importance to understand whether and how paradigmatic causal tools obtained in a classical setting can be carried over to the quantum realm. Here we show that quantum effects imply radically different predictions in the instrumental scenario. Among other results, we show that an instrumental test can be violated by entangled quantum states. Furthermore, we demonstrate such violation using a photonic set-up with active feed-forward of information, thus providing an experimental proof of this new form of non-classical behaviour. Our findings have fundamental implications in causal inference and may also lead to new applications of quantum technologies.
We present the first experimental test that distinguishes between an event-based corpuscular model (EBCM) [H. De Raedt et al.: J. Comput. Theor. Nanosci. 8 (2011) 1052] of the interaction of photons with matter and quantum mechanics. The test looks a t the interference that results as a single photon passes through a Mach-Zehnder interferometer [H. De Raedt et al.: J. Phys. Soc. Jpn. 74 (2005) 16]. The experimental results, obtained with a low-noise single-photon source [G. Brida et al.: Opt. Expr. 19 (2011) 1484], agree with the predictions of standard quantum mechanics with a reduced $chi^2$ of 0.98 and falsify the EBCM with a reduced $chi^2$ of greater than 20.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا