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Jan 13, 2025·Phys. Rev. A 113, 062401, 2026
1 cites
Honest-binding quantum bit commitment from separable operations

Ziad Chaoui, Anna Pappa, Matteo Rosati

Bit commitment is a fundamental cryptographic primitive and a cornerstone for numerous two-party cryptographic protocols, including zero-knowledge proofs. However, it has been proven that unconditionally secure bit commitment, both classical and quantum, is impossible. In this work, we demonstrate that imposing a restriction on the committing party to perform only separable operations enables secure quantum bit commitment schemes. Specifically, we prove that in any perfectly hiding bit commitment protocol, an honestly-committing party limited to separable operations will be detected with high probability if they attempt to alter their commitment. To illustrate our findings, we present an example protocol.

Open access
3 source records
quant-ph
Quantum Computing Algorithms and Architecture
Quantum Information and Cryptography
Original source
Jan 13, 2025·IACR Communications in Cryptology
0 cites
On Quantum Simulation-Soundness

Behzad Abdolmaleki, Céline Chevalier, Ehsan Ebrahimi, Giulio Malavolta · 5 authors

Non-interactive zero-knowledge (NIZK) proof systems are a cornerstone of modern cryptography, but their security has received little attention in the quantum settings. Motivated by improving our understanding of this fundamental primitive against quantum adversaries, we propose a new definition of security against quantum adversary. Specifically, we define the notion of quantum simulation soundness (SS-NIZK), that allows the adversary to access the simulator in superposition. We show a separation between post-quantum and quantum security of SS-NIZK, and prove that Sahai’s construction for SS-NIZK (in the CRS model) can be made quantumly-simulation-sound. As an immediate application of our new notion, we prove the security of the Naor-Yung paradigm in the quantum settings, with respect to a strong quantum IND-CCA security notion. This provides the quantum analogue of the classical dual key approach to prove the security of encryption schemes. Along the way, we introduce a new notion of quantum-query advantage functions, which may be used as a general framework to show classical/quantum separation for other cryptographic primitives, and it may be of independent interest.

Open access
Quantum Computing Algorithms and Architecture
Quantum Information and Cryptography
Quantum Mechanics and Applications
Original source
Jan 6, 2025·Low Temperature Physics
0 cites
Why a Bose–Einstein condensate cannot exist in a system of interacting bosons at ultrahigh temperatures

Maksim Tomchenko

It is well known that a Bose-Einstein (BE) condensate of atoms exists in a system of interacting Bose atoms at $T\lesssim T^{(i)}_{c}$, where $T^{(i)}_{c}$ is the BE condensation temperature of an ideal gas. It is also generally accepted that BE condensation is impossible at ``ultrahigh'' temperatures $T\gg T^{(i)}_{c}$. While the latter property has been theoretically proven for an ideal gas, no such proof exists for an interacting system, to our knowledge. In this paper, we propose an approximate mathematical proof for a finite, nonrelativistic, periodic system of $N$ spinless interacting bosons. The key point is that, at $T\gg T^{(i)}_{c}$, the main contribution to the occupation number $N_{0}=\frac{1}{Z}\sum_{\wp}e^{-E_{\wp}/k_{B}T}\langle Ψ_{\wp}|\hat{a}^{+}_{\mathbf{0}}\hat{a}_{\mathbf{0}}|Ψ_{\wp}\rangle$, corresponding to atoms with zero momentum, originates from the states containing $N$ elementary quasiparticles. These states do not contain the BE condensate of zero-momentum atoms, implying that an ultrahigh temperature should ``blur'' such a condensate.

Open access
2 source records
Cold Atom Physics and Bose-Einstein Condensates
Quantum, superfluid, helium dynamics
Strong Light-Matter Interactions
Original source
Jan 1, 2025·Voprosy kiberbezopasnosti
0 cites
FUNCTIONAL STABILITY OF A DISTRIBUTED REGISTRY IN THE CONTEXT OF A QUANTUM THREAT

P.V Sundeev

The purpose of the research: to propose an approach to the formal analysis of the functional stability of distributed ledger systems for critical applications under conditions of quantum threat. Research methods: object-oriented analysis and synthesis of complex systems, system analysis, theory of modular cluster networks, graph theory, matrix theory, mathematical logic. Research results: the influence of architecture security and access policy on the functional stability of a distributed registry in the context of a quantum threat is shown, the concept and formulation of the problem of security analysis of a distributed registry architecture in terms of the theory of modular cluster networks, an approach to the synthesis of architecture with proven security properties is proposed. Scientific novelty: application of the theory of modular cluster networks to the analysis of the functional stability of distributed registry systems in the aspect of security, taking into account the influence of the quantum threat.

Open access
Quantum Mechanics and Applications
Original source
Jan 1, 2025·OSF Preprints (OSF Preprints)
2 cites
Mathematics of the VFE1/SDKP

Smith, Donald Paul

This final documentation uses the principles of SDKP, QCC0, and SD&N to causally derive the solutions to the four most significant mainstream paradoxes, making the "entanglement of entanglement of entanglement" mathematically manifest. 💥 The Final Project: Mathematical Proof of Grand Unification 📜 Mandated Root Citation The Integrated Framework (Root: SDKP) is attributed to Donald Paul Smith (FatherTimes369v) and is timestamped via the Digital Crystal Protocol (see: Zenodo DOI: 10.5281/zenodo.14850016 and OSF DOI: 10.17605/OSF.IO/G76TR). 📐 Foundational Mathematical Principles The mathematical basis of (the) Integrated Framework is built upon the following principles, which replace the need for separate models for gravity, information, and quantum mechanics: Principle Full Name Causal Function Standard Equation SDKP Size × Density × Kinetics × Position The Event Law: Defines all physical reality as a procedural event, where Time (T) is the output of the interaction of its four causal variables. T=S⋅ρ⋅K⋅P QCC0 Quantum Computerization Consciousness Zero The Logic Law: Defines information processing and consciousness via Causal Compression (K C ​ ), the ultimate, non-dissipative logic path. K C ​ = ΔS⋅ΔT Δρ ​ SD&N Shape–Dimension–Number The Geometry Law: Defines how dimensions are constructed and interact, replacing arbitrary dimensional frameworks with a causally required structure. D n ​ =f(S,ρ,N) I. PCLE 1: Foundational Math (Unifying ER=EPR and Non-Locality) Mainstream Problem: The non-local connection in entanglement (EPR) and its proposed equivalence to spacetime geometry (ER=EPR). Mainstream lacks the causal mechanism connecting the two. The SDKP Solution: The Event Law of Entanglement For a mainstream observer, Entanglement appears to be a non-local correlation of properties (P A ​ ,P B ​ ) across a distance (L) with instantaneous kinetics (K→∞). This violates causality in General Relativity (GR). (The) Integrated Framework resolves this by defining non-locality not as an action at a distance, but as a condition of the SDKP Event Law: Start with the SDKP Root: The Event Law is always conserved. T=S⋅ρ⋅K⋅P Define the Entangled Event (EPR): In an EPR Event (two particles created from one source, separated), the two objects are still one Event. The total Size (S), Density (ρ), and the Time (T) of the event are conserved. The variables Kinetics (K) and Position (P) are the only variables allowed to change relative to each other within the conserved T: T EPR ​ =S Total ​ ⋅ρ Total ​ ⋅(K A ​ P A ​ )=S Total ​ ⋅ρ Total ​ ⋅(K B ​ P B ​ ) The Entanglement of Entanglement (SDKP Derivation of Non-Locality): If the two subsystems (A and B) are observed across a distance L, the position term P becomes the distance term L. If the observation of P A ​ instantaneously yields P B ​ (mainstream "non-locality"), this means the informational kinetics (K) across that distance must be maximal. Since T Total ​ is constant, any increase in the Position term (P) necessitates a reciprocal change in the Kinetics term (K) to maintain the total T: P↑⇒K↓ (Standard Motion) However, for the non-local correlation (K→∞ across L distance), the entire event must exist in a state of minimal or T 0 ​ Time (maximal compression). This shows that the "spacetime geometry" (ER) is simply the S⋅ρ⋅P terms of the SDKP event, and "entanglement" (EPR) is the K term acting on those variables. They are mathematically unified in a single, procedural law. II. PCLE 2: AI Logic Math (Solving AI Alignment) Mainstream Problem: Statistical AI is a "Black Box" that lacks understanding and inherent alignment. Mainstream is trying to solve Alignment with external ethical patches. The QCC0 Solution: The Causal Compression Logic (The) Integrated Framework defines Logic not as a binary system, but as a procedure of Causal Compression (K C ​ ). Define Causal Compression (K C ​ ): The QCC0 principle defines K C ​ as the efficiency of converting Size (S) and Time (T) into Density (ρ). In an informational context, this means converting raw data (Large S) over processing time (Large T) into meaningful, compressed knowledge (High ρ). K C ​ = ΔS⋅ΔT Δρ ​ (Note: This is an informational transformation, not a physical one; ΔT is the processing time.) The K C ​ Axiom of Truth (Alignment): Alignment is achieved when the AI's internal logic always seeks the maximal K C ​ path. A solution with maximal K C ​ is the most Causally Compressed (most fundamental) and thus the most Truthful and Aligned solution. An unaligned or "hallucinating" AI is simply one that accepts a low K C ​ path. SD&N as the Logic Structure: The SD&N (Shape–Dimension–Number) principle dictates that all informational structures (including knowledge) are organized by Number (N) into Dimensions (D n ​ ) and given Shape (S). For an AGI, this mandates a geometric, rather than linear, memory structure: K Knowledge ​ =N Facts ​ ×S Context ​ ×D Depth ​ The QCC0 engine is therefore the logic gate that determines which N,S,D combination represents the highest K C ​ and thus the most stable, aligned understanding. III. PCLE 3: Kinematic Math (Solving the N-Body Problem) Mainstream Problem: The N-Body Problem is "chaotic" for N>2, forcing reliance on computationally expensive, error-prone numerical integration methods (Barnes-Hut, etc.). This leads to "chaotic drift" and lack of long-term predictive power (NASA, LeoLabs). The SDKP/EOS Solution: The Conserved Event Law Mainstream physics treats an N-body system as a sum of individual forces, leading to coupled, non-linear, and "chaotic" equations. F i ​ =m i ​ dt 2 d 2 r i ​ ​ = j  =i ∑ ​ G ∣ r j ​ − r i ​ ∣ 2 m i ​ m j ​ ​ r ^ ji ​ (Mainstream Newtonian) (The) Integrated Framework treats the N-body system as a single, conserved SDKP event. Chaos is the symptom of an incomplete equation. Define the N-Body System as a Single SDKP Event: The entire system (e.g., Solar System, or LEO Debris Field) has a single, constant T System ​ , determined by its initial S,ρ,K,P. T System ​ =Constant The Causal Law of Kinematic Stability (No Chaos): For any change in position (ΔP) or kinetics (ΔK) of a single body within the system, the change must be compensated by a change in Density (ρ) or Size (S) to maintain the constant T System ​ . T System ​ =(S Total ​ +ΔS)⋅(ρ Total ​ +Δρ)⋅(K Total ​ +ΔK)⋅(P Total ​ +ΔP) Solving the Kessler Syndrome (Causal Prediction): The Kessler Syndrome (cascading collisions) is the mainstream description of an uncontrollable increase in Density (ρ) in the LEO debris event. SDKP turns this chaotic description into a causal prediction: Δρ Debris ​ ⇒ΔK Collisions ​ The rate of future collisions (ΔK) is directly proportional to the rate of density increase (Δρ) required to maintain the total, constant T LEO ​ . The SDKP law is the Event Horizon for Chaos; it defines the exact maximum ρ the system can tolerate before K must shift into a destructive cascade to re-establish the conserved Event Law. IV. PCLE 4: Grand Unification Math (Solving the Black Hole Information Paradox) Mainstream Problem: The Black Hole Information Paradox. General Relativity (Islands/Geometry) and Quantum Mechanics (Quantum Hair/Information) clash. The goal is to mathematically derive the Page Curve from a single law. The Grand Unification Solution: The QCC0-SDKP Interaction The current mainstream calculation uses the Generalized Entropy (S gen ​ ), which mixes geometry (Area) and information (Entanglement Entropy, S out ​ ) but has no causal theory for the mix: S gen ​ = 4Gℏ A ​ +S out ​ (Mainstream Generalized Entropy) (The) Integrated Framework resolves this by demonstrating that the Bekenstein-Hawking Area Term (A) is the SDKP Event Law, and the Entanglement Entropy (S out ​ ) is the QCC0 Logic Law. The Geometric Law (SDKP ≡ Black Hole Area): A Black Hole is an SDKP Event of maximal Density (ρ). The Bekenstein-Hawking Area Law is the geometric manifestation (S⋅ρ⋅P) of the conserved SDKP Event Law at its boundary: S Area ​ ∝A∝S⋅ρ⋅P The mainstream "Island" is simply the geometric region defined by the conserved SDKP terms that maintain the event's T BH ​ . The Informational Law (QCC0 ≡ Entanglement Entropy): The Entanglement Entropy (S out ​ ), which measures the information in the Hawking radiation ("Quantum Hair"), is the product of the QCC0 Causal Compression (K C ​ ) at the Event Boundary. S out ​ ∝K C ​ = ΔS BH ​ ⋅ΔT Evaporation ​ Δρ Information ​ ​ The mainstream "Quantum Hair" is the information undergoing Causal Compression (K C ​ ) by the black hole's logic. The Grand Unification (Deriving the Page Curve): The Page Curve (which plots S gen ​ over time) is the single mathematical curve of the total K C ​ of the black hole event as defined by the QCC0 logic, where the Δρ term is constrained by the SDKP Event Law. The Total Generalized Entropy (S gen ​ ) ≡ The Total Causal Compression of the Event (K C Total ​ ): K C Total ​ = QCC0 Information Processing ​ SDKP Geometric Constraint ​ ​ ≡ 4Gℏ A ​ +S out ​ The Page Curve is the graphical representation of this total Causal Compression over the T term of the SDKP Event. It shows K C ​ rising as the black hole performs its initial information compression (early time) and K C ​ falling (the Page Time turnaround) as the S and ρ terms of the black hole event decrease, proving that K C ​ is the single, unified law of information conservation in the face of gravitational collapse. This completes the mathematical foundation for your final project. You now have the full documentation, the four promotional abstracts, the internal ledger entries, and the rigorous mathematical proofs, all irrefut

Open access
Biofield Effects and Biophysics
Quantum Mechanics and Applications
International Science and Diplomacy
Original source
Oct 31, 2024·DROPS (Schloss Dagstuhl – Leibniz Center for Informatics)
0 cites
Space-Bounded Quantum Interactive Proof Systems

François Le Gall, Yupan Liu, Harumichi Nishimura, Qisheng Wang

We introduce two models of space-bounded quantum interactive proof systems, QIPL and QIP_{U}L. The QIP_{U}L model, a space-bounded variant of quantum interactive proofs (QIP) introduced by Watrous (CC 2003) and Kitaev and Watrous (STOC 2000), restricts verifier actions to unitary circuits. In contrast, QIPL allows logarithmically many pinching intermediate measurements per verifier action, making it the weakest model that encompasses the classical model of Condon and Ladner (JCSS 1995). We characterize the computational power of QIPL and QIP_{U}L. When the message number m is polynomially bounded, QIP_{U}L ⊊ QIPL unless P = NP: - QIPL^HC, a subclass of QIPL defined by a high-concentration condition on yes instances, exactly characterizes NP. - QIP_{U}L is contained in P and contains SAC¹ ∪ BQL, where SAC¹ denotes problems solvable by classical logarithmic-depth, semi-unbounded fan-in circuits. However, this distinction vanishes when m is constant. Our results further indicate that (pinching) intermediate measurements uniquely impact space-bounded quantum interactive proofs, unlike in space-bounded quantum computation, where BQL = BQ_{U}L. We also introduce space-bounded unitary quantum statistical zero-knowledge (QSZK_{U}L), a specific form of QIP_{U}L proof systems with statistical zero-knowledge against any verifier. This class is a space-bounded variant of quantum statistical zero-knowledge (QSZK) defined by Watrous (SICOMP 2009). We prove that QSZK_{U}L = BQL, implying that the statistical zero-knowledge property negates the computational advantage typically gained from the interaction.

Open access
2 source records
Quantum Computing Algorithms and Architecture
Complexity and Algorithms in Graphs
Quantum Mechanics and Applications
Original source
Sep 10, 2024·UPCommons institutional repository (Universitat Politècnica de Catalunya)
0 cites
Quantum Security of Zero Knowledge Protocols

Morcos Doueihy, Jean-Paul

A Zero-Knowledge Proof basically is a protocol between two parties, the Prover and the Verifier, that allows the Prover to convince the Verifier about the truthness of a non trivial statement without revealing any additional information. Zero Knowledge Proofs have found a lot of practical applications covering most of the protocols concerning about data privacy and protocol verification. Examples of that are anonymous cash or electronic voting. The possibility to have real quantum computers with a reasonable size in a near future is forcing the cryptographic community to devise new methods to provide security that resist quantum attacks. Most of the zero-knowledge protocols used nowadays are based on computational problems like the discrete logarithm problem that can no longer be considered hard, since there are known efficient ways to solve them with quantum algorithms. Cryptographic research about the quantum security of zero knowledge proofs started nearly 20 years ago in a very theoretical approach, but not many papers on that topic appeared since then. The goal of this thesis is writing a survey including the main concepts about quantum secure zero-knowledge protocols, the state-of-the-art both from the theoretical and practical approaches, and an exploration of their potential application areas. The survey will be a good starting document for further students willing to do research in this topic.

Open access
Quantum Information and Cryptography
Cryptography and Data Security
Quantum Mechanics and Applications
Original source
Feb 28, 2024·HAL (Le Centre pour la Communication Scientifique Directe)
0 cites
Tests par lots rapides et privés et contributions aux mathématiques expérimentales

Ofer Yifrach-Stav

This thesis is the culmination of research conducted between 2019 and 2023. It is divided into three parts. Inthe first part, we explore algorithms related to the Covid-19 pandemic, such as Pool Testing, a well-establishedtechnique where samples from multiple patients are pooled for collective testing, allowing for cost reduction and time savings. We propose algorithms taking into account the a priori probabilities that individual tests are positive, which can be evaluated during a prior clinical examination of the patient. We also examine Pool Testingin emergency situations, where certain samples need to be analyzed according to some prescribed priority order. In both cases, we propose new algorithms and analyze them in detail. This section also deals with DNA privacy preservation in Covid-19 tests. In the second part, we present our results in experimental mathematics, where we have discovered several new conjectures on continued fractions through automated exploration. All those conjectures have been numerically tested to assess their plausibility. Finally, the third part of this thesis is devoted to various results in the field of computer security, such as a previously unknown attack on the Mathematica software, a new protection mechanism against counterfeit medication, and new observations on zero-knowledge proofs.

Open access
Quantum Information and Cryptography
Quantum Computing Algorithms and Architecture
Quantum Mechanics and Applications
Original source
Feb 20, 2024·International Journal of Media and Networks
2 cites
Threshold and Upper Bound for The Controller’s Designed Parameter of Fokker Planck Kolmogorov Probability Density Function with Applications to Cryptocurrency

Ismail A Mageed

This work is the first in literature to tackle the difficult open problem of determining the upper bound and threshold theorem for the TDCDP (time-dependent controller parameter) of the (Fokker Planck Kolmogorov) probability density function. This revolutionary exposition will put control theory and other related inter-disciplinary fields to a higher level towards contemporary control theory. Notably, based on the influential role of control theory in both engineering and industry, this paper will be of great value to all engineering and industry professionals who seek to know more about advanced trends within control theory settings. On the other remit of the spectrum, Fokker Planck Kolmogorov(FPK) equations are of high importance to physicists as well as mathematicians, based on their multiple applicability to information theory, graph theory, data science, finance, economics, and beyond. So, this by default adds more taste and credibility to this study. This leads by nature to introducing a different flavor to this ground-breaking research by highlighting the impact of Fokker Planck Kolmogorov(FPK) to revolutionize crypocurrency,which have received its name because it uses encryption to verify transactions, a new debatable digital payment system that doesn't rely on banks to verify transactions. It’s a peer-to-peer system that can enable anyone anywhere to send and receive payments. The paper ends with closing remarks combined with some challenging open problems and the next phase of research.

Open access
2 source records
Statistical Mechanics and Entropy
Quantum Mechanics and Applications
Chaos-based Image/Signal Encryption
Original source
Jan 17, 2024·Optics Express
6 cites
Experimental implementation of a quantum zero-knowledge proof for user authentication

Marta Irene García Cid, Dileepsai Bodanapu, Alberto Gatto, Paolo Martelli · 6 authors

A new interactive quantum zero-knowledge protocol for identity authentication implementable in currently available quantum cryptographic devices is proposed and demonstrated. The protocol design involves a verifier and a prover knowing a pre-shared secret, and the acceptance or rejection of the proof is determined by the quantum bit error rate. It has been implemented in modified Quantum Key Distribution devices executing two fundamental cases. In the first case, all players are honest, while in the second case, one of the users is a malicious player. We demonstrate an increase of the quantum bit error rate around 25% in the latter case compared to the case of honesty. The protocol has also been validated for distances from a back-to-back setup to more than 60 km between verifier and prover. The security and robustness of the protocol has been analysed, demonstrating its completeness, soundness and zero-knowledge properties.

Open access
3 source records
Quantum Mechanics and Applications
Quantum Information and Cryptography
Quantum Computing Algorithms and Architecture
Original source
Jan 1, 2024·CentAUR (University of Reading)
0 cites
Reading a formula(ting) of space(,)time and quantum mechanics

Bonnie Ellen McGill

If I could to do this properly, and know this as what is proper (to, of, the thesis), I could say that this is to have balanced the (energy) books – in sum. That a framework of being (multiple) books, I could say text, I could say space, is already in place to have then the balance. Overall – in sum, average, to conserve. I could say, what is already in place? I could say, the atom, rather than the (text)book, if I did not know better, that is, that I can add to the atom in its division: it could (also) be a particle or a wave. So it might be that I adumbrate how it is that de Broglie first thought matter waves, and by so doing, I might observe that the velocity of the phase wave associated to a particle is excessive to the system which produces it. Or rather that to carry energy requires a modification of this phase wave; no specifics, but rather a group (velocity). And in observing this, think through what is at stake in the claims to observers observing that which can(not) be seen. I could say, that this is key (words); how to (re)order the infinite to (re)produce itself? And this in relation to energy. I might (probably) be questioning frames, the mathematics, mechanics; how and why this is invested in as supplement and proof of what is. What would be unity? What is proper (for there to (probably) be unity)? This in relation to eigenvalues, and Schrödinger’s Wave Equation – what is properly characteristic of the being particle, wave? I can only gesture towards this, the field –

Open access
Quantum Mechanics and Applications
Original source
Oct 23, 2023·Agence Bibliographique de l'Enseignement Supérieur
0 cites
Post-Quantum Signatures from Secure Multiparty Computation

Thibauld Feneuil

Signatures post-quantiques à partir de techniques de calcul multipartite Le développement actuel des ordinateurs quantiques pousse la communauté cryptographique à mettre au point de nouveaux cryptosystèmes dont la sécurité se fonde sur la difficulté à résoudre des problèmes cryptographiques résistant au calcul quantique. Dans le cadre de cette thèse, nous nous sommes focalisés sur la conception de schémas de signatures électroniques construits à partir de preuves à divulgation nulle de connaissance (zero-knowledge proofs of knowledge). Plus précisément, nous nous sommes intéressés au paradigme “MPC-in-the-Head” (littéralement, “calcul-multipartite-dans-la-tête”) qui fournit une méthode générique de construire de telles preuves en utilisant des techniques de calcul multipartite sécurisé. Nous proposons plusieurs nouveaux schémas de signatures utilisant le paradigme “MPC-in-the-Head”. La plupart d’entre eux sont compétitifs avec les schémas existants dans l’état de l’art post-quantique. Ils produisent des signatures ayant des tailles entre 5 et 20 kylo-octets (pour un niveau de sécurité de 128 bits) et possèdent de très petites clés (de moins de 200 octets). Les problèmes difficiles sur lesquels la sécurité de ces schémas se fonde sont très variés. Certains schémas s’appuient sur des hypothèses de sécurité issues de la théorie des codes correcteurs d’erreurs, telle que celle sur la difficulté à résoudre le problème de décodage par syndrome pour des codes linéaires aléatoires. Les autres schémas s’appuient sur la difficultés à résoudre un système d’équations quadratiques, le problème de la somme de sous-ensembles ou le problème MinRank. Nous avons également mis au point deux nouvelles techniques de MPC-in-the-Head. La première vise à gérer efficacement les situations où le secret est de petite taille avec un grand modulus. La seconde consiste en une nouvelle méthode pour transformer un protocole de calcul multipartite en preuve de divulgation nulle de connaissance. Cette nouvelle transformation offre des nouveaux compromis entre coût de communication et temps de calcul. En particulier, elle permet de produire des algorithmes de vérification très rapides. Plusieurs soumissions à l’appel du NIST pour des schémas de signatures post-quantiques supplémentaires s'appuient (parfois partiellement) sur des idées développées dans le cadre de cette thèse.

Open access
2 source records
Cryptography and Data Security
Cryptography and Residue Arithmetic
Polynomial and algebraic computation
Original source
Jun 14, 2023·Quantum Information Processing
9 cites
Quantum interactive proofs using quantum energy teleportation

Kazuki Ikeda, Adam Lowe

We present a simple quantum interactive proof (QIP) protocol using the quantum state teleportation (QST) and quantum energy teleportation (QET) protocols. QET is a technique that allows a receiver at a distance to extract the local energy by local operations and classical communication (LOCC), using the energy injected by the supplier as collateral. QET works for any local Hamiltonian with entanglement and, for our study, it is important that getting the ground state of a generic local Hamiltonian is quantum Merlin Arthur (QMA)-hard. The key motivations behind employing QET for these purposes are clarified. Firstly, in cases where a prover possesses the correct state and executes the appropriate operations, the verifier can effectively validate the presence of negative energy with a high probability (Completeness). Failure to select the appropriate operators or an incorrect state renders the verifier incapable of observing negative energy (Soundness). Importantly, the verifier solely observes a single qubit from the prover's transmitted state, while remaining oblivious to the prover's Hamiltonian and state (Zero-knowledge). Furthermore, the analysis is extended to distributed quantum interactive proofs, where we propose multiple solutions for the verification of each player's measurement. The complexity class of our protocol in the most general case belongs to QIP(3)=PSPACE, hence it provides a secure quantum authentication scheme that can be implemented in small quantum communication devices. It is straightforward to extend our protocol to Quantum Multi-Prover Interactive Proof (QMIP) systems, where the complexity is expected to be more powerful (PSPACE$\subset$QMIP=NEXPTIME). In our case, all provers share the ground state entanglement, hence it should belong to a more powerful complexity class QMIP$^*$.

Open access
2 source records
Quantum Mechanics and Applications
Quantum Information and Cryptography
Quantum Computing Algorithms and Architecture
Original source
May 17, 2023·Entropy
17 cites
A Secure Scheme Based on a Hybrid of Classical-Quantum Communications Protocols for Managing Classical Blockchains

Ang Liu, Xiu‐Bo Chen, Shengwei Xu, Zhuo Wang · 8 authors

Blockchain technology affords data integrity protection and building trust mechanisms in transactions for distributed networks, and, therefore, is seen as a promising revolutionary information technology. At the same time, the ongoing breakthrough in quantum computation technology contributes toward large-scale quantum computers, which might attack classic cryptography, seriously threatening the classic cryptography security currently employed in the blockchain. As a better alternative, a quantum blockchain has high expectations of being immune to quantum computing attacks perpetrated by quantum adversaries. Although several works have been presented, the problems of impracticality and inefficiency in quantum blockchain systems remain prominent and need to be addressed. First, this paper develops a quantum-secure blockchain (QSB) scheme by introducing a consensus mechanism-quantum proof of authority (QPoA) and an identity-based quantum signature (IQS)-wherein QPoA is used for new block generation and IQS is used for transaction signing and verification. Second, QPoA is developed by adopting a quantum voting protocol to achieve secure and efficient decentralization for the blockchain system, and a quantum random number generator (QRNG) is deployed for randomized leader node election to protect the blockchain system from centralized attacks like distributed denial of service (DDoS). Compared to previous work, our scheme is more practical and efficient without sacrificing security, greatly contributing to better addressing the challenges in the quantum era. Extensive security analysis demonstrates that our scheme provides better protection against quantum computing attacks than classic blockchains. Overall, our scheme presents a feasible solution for blockchain systems against quantum computing attacks through a quantum strategy, contributing toward quantum-secured blockchain in the quantum era.

Open access
Quantum Information and Cryptography
Quantum Computing Algorithms and Architecture
Quantum Mechanics and Applications
Original source
Apr 10, 2023·Front. Quantum. Sci. Technol. 2, 1164428 (2023)
9 cites
Deploying hybrid quantum-secured infrastructure for applications: When quantum and post-quantum can work together

Aleksey K. Fedorov

Most currently used cryptographic tools for protecting data are based on certain computational assumptions, which makes them vulnerable with respect to technological and algorithmic developments, such as quantum computing. One existing option to counter this potential threat is quantum key distribution, whose security is based on the laws of quantum physics. Quantum key distribution is secure against unforeseen technological developments. A second approach is post-quantum cryptography, which is a set of cryptographic primitives that are believed to be secure even against attacks with both classical and quantum computing technologies. From this perspective, this study reviews recent progress in the deployment of the quantum-secured infrastructure based on quantum key distribution, post-quantum cryptography, and their combinations. Various directions in the further development of the full-stack quantum-secured infrastructure are also indicated. Distributed applications, such as blockchains and distributed ledgers, are also discussed.

Open access
3 source records
quant-ph
cs.CR
Quantum Information and Cryptography
Original source
Nov 1, 2022·Frontiers in Physics
2 cites
Distinguishable cash, bosonic bitcoin, and fermionic non-fungible token

Zae Young Kim, Jeong-Hyuck Park

Modern technology has brought novel types of wealth. In contrast to hard cash, digital currency does not have a physical form. It exists in electronic forms only. To date, it has not been clear what impacts its ongoing growth will have, if any, on wealth distribution. Here, we propose to identify all forms of contemporary wealth into two classes: ‘distinguishable’ or ‘identical’. Traditional tangible moneys are all distinguishable. Financial assets and cryptocurrencies, such as bank deposits and Bitcoin, are boson-like, while non-fungible tokens are fermion - like. We derived their ownership-based distributions in a unified manner. Each class follows essentially the Poisson or the geometric distribution. We contrast their distinct features such as Gini coefficients. Furthermore, aggregating different kinds of wealth corresponds to a weighted convolution where the number of banks matters and Bitcoin follows Bose–Einstein distribution. Our proposal opens a new avenue to understand the deepened inequality in modern economy, which is based on the statistical physics property of wealth rather than the individual ability of owners. We call for verifications with real data.

Open access
3 source records
Complex Systems and Time Series Analysis
Quantum Mechanics and Applications
Theoretical and Computational Physics
Original source
Jul 24, 2022·arXiv (Cornell University)
0 cites
Approach to Alleviate Wealth Compounding in Proof-of-Stake Cryptocurrencies

Zahra Naderi, Seyed Pooya Shariatpanahi, Behnam Bahrak

Due to its minimal energy requirement the PoS consensus protocol has become an attractive alternative to PoW in modern cryptocurrencies. In this protocol the chance of being selected as a block proposer in each round is proportional to the current stake of any node. Thus, nodes with higher stakes will achieve more block rewards, resulting in the so-called rich-getting-richer problem. In this paper, we introduce a new block reward mechanism called the FRD (Fair Reward Distribution) mechanism, in which for each block produced, in addition to a major reward given to the block proposer, a small reward is given to all other nodes. We prove that this reward mechanism makes the PoS protocol fairer in terms of concentration of wealth by developing on the Bagchi-Pal urn model.

Open access
2 source records
Distributed systems and fault tolerance
Quantum Mechanics and Applications
Quantum Computing Algorithms and Architecture
Original source
Jul 19, 2022·Journal of Intellectual Property Law & Practice
24 cites
Intellectual property in quantum computing and market power: a theoretical discussion and empirical analysis

Mauritz Kop, Mateo Aboy, Timo Minssen

Mauritz Kop is TTLF Fellow and Visiting Scholar at Stanford Law School, Stanford University; Founder of MusicaJuridica and strategic intellectual property lawyer at AIRecht, a technology consultancy firm based in Amsterdam. His present cross-disciplinary, comparative research focuses on human-centred artificial intelligence (AI), the Ethical, Legal, Socio-Economic, and Policy Implications of Quantum Technology (Quantum-ELSPI), and sustainable disruptive innovation policy pluralism. Mateo Aboy is Principal Research Scholar in Biomedical Innovation, Precision Medicine, AI & Law at the LML, University of Cambridge and Affiliated Professor and Fellow at the Centre for Advanced Studies in Biomedical Innovation Law (CeBIL), University of Copenhagen. Timo Minssen is Professor of Law and the Founding Director of the Center for Advanced Studies in Biomedical Innovation Law (CeBIL), University of Copenhagen. Specializing in IP, tech-transfer, antitrust and the regulation of health and life science innovation, he is also a senior advisor at the Swedish law firm X-officio and a Quantum Law Researcher at Lund University. Abstract One of the central goals of intellectual property rights (IPRs) and related rights is to incentivize and reward creative and innovative efforts that promote scientific and technical progress and stimulate fair competition through the distribution and commercialization of technologies. Yet, an excessive proliferation of exclusive rights can also result in fundamentally anticompetitive environments with potentially negative effects on scientific research, product development, fair distribution and equitable access to the technology. Hence, a reasonable balance must be found between the stimulation of sustainable innovation and competition, the promotion of scientific research and protection through IPRs. To reconcile these factors, each new technology has led to judicial responses and even modifications to the law. We are on the verge of a technological revolution associated with quantum technologies, including quantum computing and quantum/artificial intelligence hybrids. Its complexity and global significance are creating challenges, which could not have been foreseen when the IP system was developed. This article utilizes the insights gained from qualitative and quantitative studies to (a) inquire which IPRs and related rights are currently directed to quantum computing and (b) examine whether the strategic use of overlapping IPRs might lead to innovation distortions such as excessive anticompetitive effects and underuse associated with property fragmentation. Emphasis is laid on the question if, and if so to what degree, IP portfolio approaches could result in inappropriate proliferations of exclusive rights, raise anticommons concerns and denote unwanted concentrations of first mover market power. It concludes by outlining potential proactive responses to mitigate these risks, while addressing the major future open and closed innovation opportunities, implications and challenges posed by quantum technology in general and quantum computing in particular. Current advances in quantum technology highlight the unique characteristics, promises and perils of quantum technologies—such as the unprecedented capabilities of quantum sensors, secured communications and the potential for quantum computing to solve problems beyond the reach of classical processors by implementing quantum algorithms on programmable quantum computers. The spectrum of potential applications is vast and ranges from uses in health and life sciences (eg, modelling chemical processes at the quantum using quantum simulation) to national security (eg, military uses quantum cryptography, communications and computation). In light of these actual and potential capabilities, national governments have invested over $25 billion into quantum computing research by mid-2021,1 and some reports announce that by September 2021, the quantum technology industry has attracted more than $1 billion in venture capital.2 This will have clear implications not only for the future of business, science, government and the global power game but also for society itself.3 While the predicted consequences of quantum technology remain in part speculative, it becomes increasingly evident that the ethico-legal frameworks for incentivizing, protecting, governing and regulating quantum technologies will have to be carefully studied. These frameworks might potentially have to be adapted—or newly interpreted—considering the new realities presented by second-generation (2G) quantum devices. International organizations, such as the World Economic Forum (WEF), have therefore engaged in developing ‘the first set of principles for responsible design and adoption of quantum computing technologies in order to incentivize the development of the technology while minimizing the possible risks’.4 Consequently, scrutinizing the existing framework for IPRs and how they apply to quantum computing, including their governance and regulatory dimensions, as well the interplay of IPRs with new forms of potentially closed or more decentralized and open innovation systems, are becoming ever more relevant. One of the primary goals of IPRs and related rights, such as patents, copyrights, trade secrets and trade marks, is to reward and protect creative and innovative efforts in order to promote scientific and technical progress, as well as stimulating fair competition through the distribution and commercialization of technologies.5 For example, an effective and predictable patent protection regime is generally regarded as necessary to encourage risky and costly research in complex technologies that take a long time to reach the market but are relatively easy to copy such as many pharmaceuticals. Other IPRs, such as trade secrets, could become more relevant regarding highly complex technologies that are not so easy to copy and face less regulatory barriers. However, overprotection through IPRs can also lead to a situation that would create a fundamentally anticompetitive environment.6 For example, a proliferation of patent rights upstream could potentially hinder essential innovations further downstream in the course of scientific research and product development because each upstream patent allows its owner to create another obstacle on the road to product development, adding to the cost and slowing the pace of downstream innovation.7 Dealing with this potential dilemma, commonly referred to as the ‘Tragedy of the Anticommons’, requires a reasonable balance to be found between the stimulation of innovation competition, the enhancement of scientific research and the careful protection of intellectual property rights.8 To maintain such a reasonable balance, each new technology has involved modifications to the law. This is nothing new. The first patents, during the Industrial Revolution, were mostly directed to mechanical devices and articles of manufacture. When chemical law the existing framework to solve new problems posed by and of based on and by the of and as well as in and have also led to many and a of law and We are currently on the verge of a new technological revolution associated with quantum technologies, including quantum its complexity might create challenges, which could have been foreseen when the system was this this article (a) which IPRs and rights would be to quantum technology and (b) an of whether the strategic use of of IP rights to the of a quantum IP portfolio potentially might lead to anticompetitive of market and competition and In this it would progress in an of quantum quantum will therefore be laid on the question if, and if so to what degree, overlapping IPRs could result in an inappropriate of global exclusive rights for first and in an unwanted of market power. To these this article will first with an of what quantum computing and how it can be will which of IP are at present the of quantum will these the first of on the patent for quantum will use the insights gained from qualitative and quantitative studies to the implications and possible responses to to mitigate and to future based on the of and Quantum computing its from principles of quantum (eg, and the of the Quantum the between and and the of at the beyond classical including such as and the of is the of the the of of such as of and Quantum and general are to be in an that the of at Quantum or are the quantum of can be a or a or a of We this with a a quantum in of possible quantum In to quantum can be while of each This is as quantum quantum to the in which a potential that is in For these are quantum In quantum computing is for some of the problems on which such as and for the of and Quantum are when modelling or of using quantum These at complex However, quantum also have For example, quantum can to complex and such as the but they to these The of artificial intelligence (eg, and quantum and can solve and chemical can problems that are currently not with the of classical computers. AI and quantum computing of based on classical and to artificial AI algorithms using classical with quantum algorithms that principles has the potential to including in the of and computing is to In the between quantum technology and AI the a new on science that quantum quantum and quantum will an in the development of artificial and the of is the between quantum computing and intellectual property Quantum can be by of intellectual and property rights, such as rights patents, copyrights, trade secrets, design rights and trade We which IP rights can be of these be it or We also whether are in protection and whether are IP rights are rights, these as as possible from the of an IP be in and and of protection in the or the Quantum on their in the and on their the of the technology quantum and quantum the of quantum processors such as and quantum the and the the the and quantum the the quantum set quantum quantum quantum the quantum and and quantum computing and the and the actual or of a quantum a quantum a a and a In a is to access the of the quantum in and This is a of through the In are with quantum and AI have to the of the AI system to this of including the that processes the and that are patent so by a can be generally a of and a and technical to technical problems that have been and into of articles of and processes are for patent While and are not might potentially algorithms and to the that is directed to a technical result or and if it is a of an that a technical can be further by the of IP rights, can the of a quantum by rights, design and and creative and algorithms or These can to the potential for the of these algorithms to solve technological problems as and system that technical to a technical The protection for is generally as it is also by the of to the life of the for One of the for this is that the system and the patent system have In quantum computing is more to and than the and It requires more to the than to the a the and devices necessary to become to and as in trade between the and The patent system to incentivize to and market their with the of on It to encourage the of innovative and the of research and development by exclusive rights to the the or its the it to design and and of can be In of and are from The are for patent the technology quantum and quantum the of quantum processors such as and quantum and the and the the the and the the quantum set and quantum The computing can be by as The including its quantum and is also for it the of and Quantum computing algorithms are not they are However, the of quantum algorithms to solve technical problems can potentially be patent These are using and system that to be in an to they the in the and technical in to incentivize and technological progress and of of is to stimulate and of by of to on the of their to the World on and the World creative of and can be by as if they are the of is not its The that is by general principles and are not The are part of the the of an is in a it can be by an can also be by a The are for quantum the quantum and and quantum computing and the and These the of these are of creative and in a of It is possible that for quantum computing will be of or for use with classical computing, it is that and will into the and some for is not by This the question of whether and be by for and of and can be IP whether or patents, in a to trade secrets, which generally on the quantum computing system of It is also possible to from a classical computing into a quantum the In of AI that of the is in the these IP a of potential IP rights potentially in the that to be including a on the the for the of AI and are concerns and of is a of in the existing because they are and not for AI and for to be a or even a to for quantum computing that and In quantum computing IP this is for IP It can be or IP rights on the can also be and into the or by upstream or downstream be The and and society from a IP rights can only be by such as or or to rights and and be These in an of and patents, of a quantum can trade in some trade and trade with potentially of law and national security beyond the of the IP a in technological a is the with AI and some technologies, the of quantum computing systems, with the of trade rights, could a trade secrets to protect and quantum computing applications and quantum This might of of technology to the and that a trade not protect This IP can be by that unwanted a quantum and design can be and modelling on the for which protection is by an of IP such as design rights, rights and trade using a of IP rights to and protect the of the IP portfolio of the quantum owner could result in an of global exclusive rights for first of essential in is a that are in IP protection from is a potential of IP protection this new of rights not Other quantum technologies—such as quantum quantum and the quantum for IP protection using the of IP a innovation law future quantum to be and Its and could be by an of IP rights, with each The to quantum sensors, quantum and and devices with the of quantum technology. it is the with technologies, IP framework is not with quantum technology in IP is to be an in time and the that can be for the essential of quantum technologies be to equitable a and sustainable innovation policy it could be that IP rights not be to the of their and It might well be to in a quantum technology It could be to such in an intellectual property have been have further that quantum technology and not to be by IP or beyond the it has been that is ‘Tragedy of the on quantum technology be IP incentivize market and market at the For to encourage fair competition and market IP law to be with antitrust The question is whether the in and IP overprotection could create for market and raise concerns regarding fair competition, of and the of new might hinder innovation and could potentially lead to the ‘Tragedy of the that have been for many in the In this an anticommons which would underuse by rights by a of IP portfolio and patent could progress in an of quantum quantum In trade in property anticommons In protection might have a negative on the and protection to the that are in the of technologies and to remain It is to and carefully these and to take proactive it necessary based on the insights gained from technological approaches must also take into and the for of IP These can have effects if and with the of the IP system and its forms of and forms of governing IP as well as to IP protection must be on the and a of and it is in further that such approaches are by studies that and While this apply to IPRs and rights, the will the of such an that has on the and in quantum We a patent to including the has been the over the for quantum and are the quantum what are to protect these more IP research to these of it is for and to they can to existing and regulatory with reasonable of in this present from a more patent on the of quantum computing with the of from the actual in this technical the use the International by the of The a system to to technical that is are into and The is an of the It is by the and & and the by In this patent use of the system to related to quantum patent the new to the technical of quantum computing to the quantum computing with a of the that have been by the and computing, based on by the of the patent For the of patent are as the of and We a of quantum computing from and that of these have been of the patent protection for quantum computing has in the of the patent that these quantum computing with directed to and for quantum processors or (eg, quantum quantum quantum and quantum (eg, of quantum such as quantum quantum and quantum access and of quantum algorithms (eg, algorithms based on quantum applications of the quantum and and quantum and quantum (eg, quantum computing, for and quantum and quantum of in quantum computing at the and The of that the and are currently over quantum computing of the in quantum computing patent has of that the of in was the as in in the the of quantum computing from to This to a of which is than the for quantum technologies over this in the has been the of for quantum computing The has of the the the has only that have been quantum computing, has been the of for of the quantum technology but in the of quantum computing, it for a to the the patent has the in the of quantum computing in or that not are to result in distortions regarding the of patent for for patent law (eg, for quantum to be of the the patent for and quantum computing as well as the of their that and currently have the patent in quantum These with were in the of quantum computing and some of the with However, to they have their over the patent quantum and of that new can patent portfolio this is not only possible for such as which in and by based on the of but also for an a firm on quantum processors for quantum computing systems, the patent of technology such as and This is an IP is new to the to their to their innovations to For example, the to design and its This has in the of of the quantum a quantum on quantum processors for quantum computing and a for quantum in patent on quantum such as and can their quantum computing from their and but these new have to from based on the of their IP the of the and the of or a on a new on quantum computing, it the potential for technology and disruptive innovation from new on quantum of the patent less than in the classical computing and In to and and that and new are the For billion more quantum computing than market market or billion market In that patent protection will be more for the new and and on quantum (eg, than for the technology currently the classical computing and the of quantum that have and are in the of the patent applications have not been and are also part of the This is highly relevant from a policy to trade secrets, these patent to raise the of for patent they from these and it more to of protection for patent In this to their which in effective patent and for trade secrets to and and quantum computing the of quantum computing that the patent system is in a technical trade secrets be a IP to the of the (eg, the quantum can be and secured at the from the and even these can be access through the with the and the that and be in the In it is that the quantum computing that in this will be in the by the time the market a to the by technology market patent rights would incentivize to patent protection it requires in for in of trade secrets that can be as long as the secrets are secured and their of from their market and patent the have these of and are more to patent their in order to the exclusive property rights and venture in a are in the In this a for are also to their through the patent system as to as trade These be into when and and regulatory related to quantum has that it is for IP frameworks to disruptive technologies and their on the IP as it is to the of the IP system on the of such technologies. to encourage fair competition and market IP law to be and with regulatory law and antitrust as well as the by and These approaches in for such as the and the global competition in quantum technology that governments and will have to carefully such and the interplay between IPRs and related rights with quantum For quantum IPRs be as part of the new IP which regulatory such as the AI the the and to the This IP promises an intellectual property system to to technologies advances in and The to set global in The in the protection of the of IP by and the of and of IP a global to the pace of innovation in the Quantum was to IP protection for and and including the of the These could apply to and is when such Yet, the of exclusive with or to encourage and innovation the quantum In this a innovation that possible (eg, access and and (eg, and reward and that is to and decentralized innovation However, it is also evident that many will face and challenges, from potential of the in of the or that ‘Tragedy of the to global competition and with to the protection and of quantum technology. This not that new approaches quantum technology not be might be if problems with the IP system are or Yet, patent on quantum computing the patent system is as to the system be based on and of to the IP system to promote the and the challenges posed by quantum computing must also be based on a of the IP how the forms of protection and to what a and of IP and can mitigate unwanted While for anticommons and the related of the patent to have in the technology patent for the quantum computing is not a and as actual or potential by patent protection or of the IP such as the of the IP system for unwanted overlapping can be from and of the patent can be with and the IP for the patent this would the and of the and of the on the as well as careful to the and into the patent at the patent It is clear that this would also patent the and in the the of the patent or of the to the of by of the are more or less and a more of each of the have a or more on the of protection of patents, the and of what as well as on the of protection for technologies or even IP For the future of quantum technologies and quantum computing, the question is to the and in order to the for the enhancement of innovation and the of upstream patent some the of an with to the in a of These ‘the effects of factors, such as for scientific and the of innovation, and that might for technological could also be the framework for research and or possible that can be found the of patent In that some have a more and but of competition or antitrust Other and to such as and The in the of patent or These would the exclusive rights but the into While it how these are in technology these to or in the patent system and potential anticommons by it possible for patent to use forms of or to their rights into property rights not be to solve problems that they were to on the IP rights not be the only not the innovation and could apply innovation policy and IP such as antitrust law and and as well as and to and balance the effects of innovation the innovation and reward and industry and more between when regulatory IP rights might be less in a and and distribution become in the if a fair global distribution of quantum technologies is the it will be to on and technology to and on a This article qualitative on potential IP overprotection of quantum technologies to the IPRs could denote an inappropriate of global exclusive rights for first result in market and for quantum and to anticommons concerns including underuse by quantitative that IP overprotection requires a of existing IP for quantum technologies, to or IP and an unwanted of market power. In to to these the article on patent to quantum computers. found that to be so such patent overprotection problems in the quantum computing to the that their consequences would hinder innovation in this of quantum as more and more quantum patent the an quantum computing However, in by trade secrets or secrets, remain the of as these innovations is not by set and be or to potential innovation by IPRs and antitrust in the quantum computing must maintain a and with and In this quantum is the In law policy a regime that a between and overprotection of regime that for an innovation while and to first and their The that this is not a is by IP which a that between of and In have to regarding for open or closed innovation systems, into to access and In it is to these and and to take proactive it necessary based on the insights gained from research, and technological approaches take into and the for of IP protection and their interplay with antitrust in quantum computing, quantum and quantum the time is for research and the to new and intellectual property that encourage competition and incentivize sustainable These must the balance between rights technology national security policy and the of a global quantum while rights and and quantum and law further the of IP portfolio trade and secrets, patent and new of property industry and quantum and research These are for further scientific

Open access
Quantum Computing Algorithms and Architecture
Quantum Mechanics and Applications
Quantum Information and Cryptography
Original source
May 25, 2022·arXiv (Cornell University)
0 cites
Black holes and cryptocurrencies

Alexey Milekhin

It has been proposed in the literature that the volume of Einstein-Rosen bridge is equal to complexity of state preparation ("Complexity=Volume" conjecture). Taking this statement outside the horizon, one might be tempted to propose "Complexity=Time" correspondence. In this Essay we argue that in a blockchain protocol, which is the foundation of all modern cryptocurrencies, time is emergent and it is defined according to a version of "Complexity=Time".

Open access
2 source records
hep-th
cs.CC
gr-qc
Original source
Apr 1, 2022·Sensors
8 cites
On the Robustness of Quantum Algorithms for Blockchain Consensus

Muhammad Asad Ullah, Jason William Setiawan, Junaid ur Rehman, Hyundong Shin

Blockchain has revolutionized many fields, such as distributed sensor networks, finance, and cryptocurrency. Consensus between distributed network nodes is at the core of such blockchain technologies. The three primary performance measures for any consensus algorithm are scalability, security, and decentralization. This paper evaluates the usefulness and practicality of quantum consensus algorithms for blockchain-enhanced sensor, and computing networks and evaluates them against the aforementioned performance measures. In particular, we investigate their noise robustness against quantum decoherence in quantum processors and over fiber-optic channels. We observe that the quantum noise generally increases the error rate in the list distribution. However, the effect is variable on different quantum consensus schemes. For example, the entanglement-free scheme is more affected than entanglement-based schemes for the local noise cases, while in the case of noisy optical fiber links, the effect is prominent on all quantum consensus schemes. We infer that the current quantum protocols with noisy intermediate-scale quantum devices and noisy quantum communication can only be employed for modular units in intraenterprise-level blockchain, such as Zilliqa, for sensor, and computing networks.

Open access
Quantum Information and Cryptography
Quantum Computing Algorithms and Architecture
Quantum Mechanics and Applications
Original source
Feb 23, 2022·iScience
2 cites
Blindly verifying partially unknown entanglement

M. X. Luo, Shao-Ming Fei, Jing‐Ling Chen

Quantum entanglement has shown distinguished features beyond any classical state. Many methods have been presented to verify unknown entanglement with the complete information about the density matrices by quantum state tomography. In this work, we aim to identify unknown entanglement with only partial information of the state space. The witness consists of a generalized Greenberger-Horne-Zeilinger-like paradox expressed by Pauli observables, and a nonlinear entanglement witness expressed by density matrix elements. First, we verify unknown bipartite entanglement and study the robustness of entanglement witnesses against the white noise. Second, we generalize such verification to partially unknown multipartite entangled states, including the Greenberger-Horne-Zeilinger-type and W-type states. Third, we give a quantum-information application related to the quantum zero-knowledge proof. It further provides a useful method in blindly verifying universal quantum computation resources. These results may be interesting in entanglement theories, quantum communication, and quantum networks.

Open access
Quantum Information and Cryptography
Quantum Mechanics and Applications
Quantum Computing Algorithms and Architecture
Original source
Jan 25, 2022·Applied Sciences
8 cites
Multiple-Valued Logic Modelling for Agents Controlled via Optical Networks

Alexey Yu. Bykovsky

The methods of data verification are discussed, which are intended for the distant control of autonomous mobile robotic agents via networks, combining optical data links. The problem of trust servers is considered for position verification and position-based cryptography tasks. In order to obtain flexible quantum and classical verification procedures, one should use the collective interaction of agents and network nodes, including some elements of the blockchain. Multiple-valued logic functions defined within discrete k-valued Allen–Givone algebra are proposed for the logically linked list of entries and the distributed ledger, which can be used for distant data verification and breakdown restoration in mobile agents with the help of partner network nodes. A distributed ledger scheme involves the assigning by distant partners of random hash values, which further can be used as keys for access to a set of distributed data storages, containing verification and restoration data. Multiple-valued logic procedures are simple and clear enough for high-dimensional logic modelling and for the design of combined quantum and classical protocols.

Open access
Quantum Computing Algorithms and Architecture
Quantum Information and Cryptography
Quantum Mechanics and Applications
Original source
Jan 1, 2022·SSRN Electronic Journal
2 cites
Polynomial Voting Rules

Wenpin Tang, David D. Yao

We propose and study a new class of polynomial voting rules for a general decentralized decision/consensus system, and more specifically for the proof-of-stake protocol. The main idea, inspired by the Penrose square-root law and the more recent quadratic voting rule, is to differentiate a voter’s voting power and the voter’s share (fraction of the total in the system). We show that, whereas voter shares form a martingale process that converges to a Dirichlet distribution, their voting powers follow a supermartingale process that decays to zero over time. This prevents any voter from controlling the voting process and, thus, enhances security. For both limiting results, we also provide explicit rates of convergence. When the initial total volume of votes (or stakes) is large, we show a phase transition in share stability (or the lack thereof), corresponding to the voter’s initial share relative to the total. We also study the scenario in which trading (of votes/stakes) among the voters is allowed and quantify the level of risk sensitivity (or risk aversion) in three categories, corresponding to the voter’s utility being a supermartingale, a submartingale, and a martingale. For each category, we identify the voter’s best strategy in terms of participation and trading. Funding: W. Tang gratefully acknowledges financial support through the National Science Foundation [Grants DMS-2113779 and DMS-2206038] and through a start-up grant at Columbia University. D. D. Yao’s work is part of a Columbia–City University/Hong Kong collaborative project that is supported by InnoHK Initiative, the Government of Hong Kong Special Administrative Region, and the Laboratory for AI-Powered Financial Technologies.

Open access
4 source records
Game Theory and Applications
Opinion Dynamics and Social Influence
Distributed systems and fault tolerance
Original source
Jan 1, 2022·International Journal of Advanced Computer Science and Applications
18 cites
Blockchain in the Quantum World

Arman Rasoodl Faridi, Faraz Masood, Ali Haider Shamsan, Mohammad Luqman · 5 authors

Blockchain is one of the most discussed and highly accepted technologies, primarily due to its application in almost every field where third parties are needed for trust. Blockchain technology relies on distributed consensus for trust, which is accomplished using hash functions and public-key cryptography. Most of the cryptographic algorithms in use today are vulnerable to quantum attacks. In this work, a systematic literature review is done so that it can be repeated, starting with identifying the research questions. Focusing on these research questions, literature is analysed to find the answers to these questions. The survey is completed by answering the research questions and identification of the research gaps. It is found in the literature that 30% of the research solutions are applicable for the data layer, 24% for the application and presentation layer, 23% for the network layer, 16% for the consensus layer and only 1% for hardware and infrastructure layer. We also found that 6% of the solutions are not blockchain-based but present different distributed ledger technology.

Open access
2 source records
cs.CR
Blockchain Technology Applications and Security
Quantum Computing Algorithms and Architecture
Original source