Blockchain Papers

Vishal Pareek, Chinmoy Biswas, Aditi Kar Gangopadhyay, Sugata Gangopadhyay

No abstract is available for this record.

Vinayak Musale, Nishinth Venkatesh, Ayush Dhore, Neel Karnavat · 7 authors

With the rise in need of Electronic Health Records (EHR), keeping confidentiality, integrity, and privacy intact of Patient Health Information (PHI) becomes of utmost importance, particularly while sharing via email which is inherently non-secure. The current work proposes a hybrid encryption approach on the basis of Advanced Encryption Standard (AES-256) with symmetric key cryptography and Elliptic Curve Cryptography (ECC) as asymmetric encryption. AES-256 is selected because it performs well to encrypt large datasets, and ECC provides secure key exchange and digital signature support with less computation overhead compared to RSA. The system addresses issues of key encryption, such as secure transmission of information, identification authentication, and digital signatures for message integrity.Besides AES and ECC, the system incorporates a Zero-Knowledge Proof (ZKP) protocol, enabling privacy-preserving identity authentication without exposing sensitive data. This is important in ensuring PHI protection because ZKP permits identity and message authenticity verification with private data left secure. The hybrid system is balanced between speed of encryption and security, such that it remains scalable and usable for real-time healthcare use cases. By integrating AES for quick data encryption, ECC for secure key management, and ZKP for added privacy, this solution provides an end-to-end solution for securely sending PHI through email. It successfully solves encryption issues while maintaining confidentiality, integrity, and privacy in healthcare communication without compromising efficiency. This encryption framework ensures compliance with major data privacy regulations including HIPAA and GDPR, making it applicable for real-world healthcare environments across both the U.S. and the EU.

Nelson Lungu, Bibhuti Bhusan Dash, Satyendr Singh, Manoj Ranjan Mishra · 6 authors

Privacy-preserving analytics is indeed a critical enabler for businesses that want to glean insights from sensitive data while protecting individual privacy. Tighter regulation and growing concern over data abuse have, respectively, driven the development of techniques involving zero-knowledge proofs and secure multiparty computation. These systems are set to establish trust boundaries among partner organisations while gently permitting significant information transfers for the decision-making process. The practically verifiable assurance of data secrecy is what makes these protocols particularly attractive in sectors heavily reliant on data analysis, like healthcare, banking, and law enforcement. Such integrated architectures guarantee controlled overhead while delivering high-quality output through cryptographic primitives. Real-life implementations show that it is indeed possible to strike a balance between the efficiency of the system and its security constraints. Enhanced Interoperabillty, along with modularity, will allow more widespread use in diverse ecosystems where insights derived from data drive enterprise innovation alongside robust privacy protections.

Yancheng Zhang, Mengxin Zheng, Xun Chen, Jingtong Hu · 8 authors

In the context of cloud computing, services are held on cloud servers, where the clients send their data to the server and obtain the results returned by server. However, the computation, data and results are prone to tampering due to the vulnerabilities on the server side. Thus, verifying the integrity of computation is important in the client-server setting. The cryptographic method known as Zero-Knowledge Proof (ZKP) is renowned for facilitating private and verifiable computing. ZKP allows the client to validate that the results from the server are computed correctly without violating the privacy of the server’s intellectual property. Zero-Knowledge Succinct NonInteractive Argument of Knowledge (zkSNARKs), in particular, has been widely applied in various applications like blockchain and verifiable machine learning. Despite their popularity, existing zkSNARKs approaches remain highly computationally intensive. For instance, even basic operations like matrix multiplication require an extensive number of constraints, resulting in significant overhead. In addressing this challenge, we introduce $z k V C$, which optimizes the ZKP computation for matrix multiplication, enabling rapid proof generation on the server side and efficient verification on the client side. zkVC integrates optimized ZKP modules, such as Constraint-reduced Polynomial Circuit (CRPC) and Prefix-Sum Query (PSQ), collectively yielding a more than $\mathbf{1 2}$-fold increase in proof speed over prior methods. The code is available at https://github.com/UCF-Lou-Lab-PET/zkformer.

Alhad Daftardar, Jianqiao Mo, Joey Ah-kiow, Benedikt Bünz · 7 authors

Zero-Knowledge Proofs (ZKPs) are a rapidly growing technique for privacy-preserving and verifiable computation.ZKPs enable one party (a prover: P) to prove to another (a verifier: V) that a statement is true or correct without revealing any additional information.This powerful capability has led to ZKPs being applied and proposed for application in blockchain technologies, verifiable machine learning, and electronic voting.However, ZKPs have yet to see widespread, ubiquitous adoption due to the exceptionally high computational complexity of the proving process.Naturally, there has been recent work to accelerate ZKP primitives and protocols using GPUs and ASICs.However, the protocols considered so far face one of two challenges: they require a trusted setup for each new application or generate large proofs with high verification costs, limiting their applicability in scenarios with numerous verifiers or strict verification time constraints.HyperPlonk is a state-of-theart ZKP protocol that supports both one-time, universal setup and small proof sizes/verification costs expected by publicly verifiable, consensus-based systems (e.g., blockchain).While HyperPlonk's setup and verifier properties are highly desirable, the proving phase is costly.A HyperPlonk prover must compute on large bitwidths (e.g., 255-381b) and polynomials (e.g., of degree 2 24 ), employs computationally (e.g., MSM) and bandwidth (e.g., SumCheck) intensive kernels, and the complete protocol comprises many steps, each constituting distinct kernels.We present an accelerator, zkSpeed, to

Rares Ifrim, Decebal Popescu

Popular technologies such as blockchain and zero-knowledge proof, which have already entered the enterprise space, heavily use cryptography as the core of their protocol stack. One of the most used systems in this regard is Elliptic Curve Cryptography, precisely the point multiplication operation, which provides the security assumption for all applications that use this system. As this operation is computationally intensive, one solution is to offload it to specialized accelerators to provide better throughput and increased efficiency. In this paper, we explore the use of Field Programmable Gate Arrays (FPGAs) and the High-Level Synthesis framework of AMD Vitis in designing an elliptic curve point arithmetic unit (point adder) for the secp256k1 curve. We show how task-level parallel programming and data streaming are used in designing a RISC processor-like architecture to provide pipeline parallelism and increase the throughput of the point adder unit. We also show how to efficiently use the proposed processor architecture by designing a point multiplication scheduler capable of scheduling multiple batches of elliptic curve points to utilize the point adder unit efficiently. Finally, we evaluate our design on an AMD-Xilinx Alveo-family FPGA and show that our point arithmetic processor has better throughput and frequency than related work.

Jules Maire, Damien Vergnaud

We present a communication-efficient zero-knowledge proof of knowledge for the factorization of Blum integers, a special class of integers of the form n = p q , where p and q are distinct prime numbers satisfying p ≡ q ≡ 3 mod 4 and p ≃ q ≃ n . Existing protocols for proving such statements often incur significant communication costs, especially when demonstrating that p and q are of nearly equal size. We leverage the MPC-in-the-head paradigm, a cryptographic technique that transforms secure multi-party computation protocols into efficient zero-knowledge proof systems. In our protocol, the prover uses additive sharing of p and q over the integers. This approach simplifies proving the size relationship p ≃ q ≃ n and the congruence p ≡ q ≡ 3 mod 4 without requiring costly range proofs. To verify the primality of p and q , we employ the Boneh-Franklin biprimality test. Our protocol achieves a significant reduction in communication complexity. For a 2048-bit integer n and 128-bit security, we construct a proof as small as 12.3 KB, with prover and verifier computational costs comparable to existing protocols that require over 131 KB.

Luís T. A. N. Brandão, René Peralta

This is the NIST Threshold Call, calling for public submissions of multi-party threshold schemes, and other related crypto-systems, to support the United States’ National Institute of Standards and Technology (NIST) in gathering a public body of reference materials unadvanced cryptography. In a threshold scheme, a reference cryptographic primitive (e.g., signing, encryption, decryption, key generation) is computed in a distributed manner, while its private/secret key is or becomes secret-shared across various parties. The threshold schemes submitted in reply to this call will be interchangeable with a reference no threshold primitive of interest, in the sense that their outputs can be used interchangeably in a subsequent operation. The primitives of interest are organized into various categories, across two classes: Class N, for selected NIST-specified primitives; and Class S, for special primitives that are not specified by NIST but are threshold friendly or have useful functional features. The scope of Class S also includes fully homomorphic encryption, zero-knowledge proofs, and auxiliary gadgets. This document specifies submission phases, and the requirements for submitting a package, including a technical specification, a reference implementation, and a report on experimental evaluation. A subsequent phase of public analysis will support the elaboration of a characterization report, which may help assess new interests beyond the cryptographic techniques currently standardized by NIST, and may include recommendations for future processes.

Md. Sameeruddin Khan, Tom Chen, Mithileysh Sathiyanarayanan, Mohammed Mujeerulla · 5 authors

The Internet of Things (IoT) model is presented in this paper with multi-layer security based on the Lenstra-Lenstra-Lovasz (LLL) algorithm. End nodes for the Internet of Things include inexpensive gadgets like the Raspberry Pi and Arduino boards. It is not practical to run rigorous algorithms on them, as opposed to computer systems. Therefore, a cryptography procedure is required that could function on this IOT equipment. Bitcoins and Ethereum are examples of cryptocurrency and Ripple employs techniques such as elliptic curve digital signature, Elliptic-Curve Diffie-Hellman (ECDH), and algorithm to sign any cryptocurrency on SECP256k1 elliptic curves transactions. By using Lenstra-Lenstra-Lovasz on a real-world Bitcoin blockchain and applying it to multiple dimensions, such as nonce leakage and weak nonces across several elliptic curves with different bit sizes on a Raspberry Pi, we can demonstrate the security of elliptic curve cryptosystems. Public key encryption techniques are seriously threatened by the development of quantum computing. Therefore, employing lattice encryption with Nth Degree Truncated Polynomial Ring Units (NTRU-NTH) on the Bitcoin blockchain will increase the resistance of Bitcoin blocks to quantum computing assaults. The execution time taken on SECP256k1 is 131.7 Milli seconds comparatively faster than NIST-224P and NIST-384P.

Shital Girme, Rushi Balapure, Prachi Patil, Sameer Patil · 5 authors

The rise of cryptocurrencies and decentralized fi- nance (DeFi) has highlighted the importance of secure and collaborative management systems for digital assets. Multi-party crypto vaults provide a way to ensure distributed control, privacy, and fault tolerance by involving multiple participants in the management and approval of transactions. This paper explores the two primary approaches—Multi-Signature (Multi-Sig) and Multi-Party Computation (MPC)—that underpin these vaults. Multi-Sig schemes offer fast, scalable solutions for real-time applications, while MPC ensures strong privacy and security by allowing encrypted computations without exposing private keys. In addition key management models, such as split-key and blockchain-based methods, and fault tolerance mechanisms, including social recovery and time-locked protocols, which ensure that vault systems remain secure and operational even in cases of participant failure. This paper recommends MPC as the optimal approach for high-security, privacy-sensitive applications, such as institutional custody and financial systems, while outlining av- enues for future research, including post-quantum cryptography and latency reduction in MPC protocols. Index Terms—Multi-Party Computation (MPC), Multi- Signature (Multi-Sig), Crypto Vaults, Threshold Cryptography, Blockchain Key Management, Decentralized Finance (DeFi),, Threshold ECDSA, Social Recovery Mechanism, Time-Locked Withdrawal Protocol, Fault Tolerance in Cryptography, Split- Key Management, Smart Contracts, Privacy-Preserving Cryp- tography, Institutional Crypto Custody

Zhuoran Ji, Jianyu Zhao, Peimin Gao, Xiangkai Yin · 5 authors

Zero-knowledge proofs validate statements without revealing any information, pivotal for applications such as verifiable outsourcing and digital currencies. However, their broad adoption is limited by the prolonged proof generation times, mainly due to two operations: Multi-Scalar Multiplication (MSM) and Number Theoretic Transform (NTT). While MSM has been efficiently accelerated using multi-GPU systems, NTT has not, due to the high inter-GPU communication overhead incurred by its permutation data access pattern.

Cheng Wang, Mingyu Gao

Zero-knowledge proof (ZKP) is an important cryptographic tool that sees wide applications in real-world scenarios where privacy must be protected, including privacy-preserving blockchains and zero-knowledge machine learning. Existing ZKP acceleration approaches using GPUs, FPGAs, and ASICs focus only on classic protocols that rely on expensive elliptic curve arithmetics. Emerging ZKP protocols based on hash functions can greatly reduce the algorithmic complexity, but they also introduce much more diverse computation kernels that cannot be efficiently handled by a single accelerator chip if dedicated units for each kernel are used. Our approach is to leverage a unified hardware architecture that is able to efficiently support the common primitives in ZKP, and then use smart mapping strategies to flexibly map various kernels to such hardware while ensuring high resource utilization. We design UniZK as such a ZKP accelerator, with a systolic-array-based hardware architecture enhanced with extra local links and a new vector processing mode. We propose novel mapping strategies to support diverse kernels including number theoretic transforms, hash functions, and general polynomial computations. UniZK provides 97x and 46x speedups on average compared to the CPU and GPU implementations of the same protocols, and is also 840x faster than previous ZKP accelerators using different protocols.

Chen-Xun Weng, Mingyang Li, Naitao Xu, Yanglin Hu · 9 authors

Zero-knowledge proofs (ZKPs) are widely applied in digital economies, such as cryptocurrencies and smart contracts, for establishing trust and privacy between untrusted parties. Classical ZKPs rely on computational assumptions and are vulnerable to quantum attacks. While a recent advance suggests quantum-sound symmetric relativistic ZKPs for the graph three-coloring problem without computational assumptions, the high round complexity, which leads to unachievable runtime and overall randomness cost, renders them impractical for real-life deployment. To overcome this, we develop an efficient asymmetric relativistic ZKP protocol using relativistic bit commitments, and prove its quantum soundness by relating it to the nonlocal Clauser-Horne-Shimony-Holt (CHSH) game. Our protocol achieves a linear relationship between the round complexity and the number of edges, and thus significantly improves practical feasibility. In addition, we implement a proof-of-principle experiment which completes all interactive rounds in about 0.22 seconds and requires an overall randomness cost of 430.81 MB. Our work illustrates the powerful potential of integrating special relativity with quantum theory in trustless cryptography, paving the way for robust applications against quantum attacks in distrustful Internet environments. Zero-knowledge proofs can protect privacy online, but almost all current methods are vulnerable to quantum attacks. Here, the authors report an efficient relativistic protocol and experiment that resists quantum attacks and greatly reduces runtime, randomness cost and communication rounds.

Nojan Sheybani, Gong, Tengkai, Anees Ahmed, Nges Brian Njungle · 6 authors

Collision-resistant cryptographic hash functions (CRHs) are crucial for security, particularly for message authentication in Zero-knowledge Proof (ZKP) applications. However, traditional CRHs like SHA-2 or SHA-3, while optimized for CPUs, generate large circuits, rendering them inefficient in the ZK domain. Conversely, ZK-friendly hashes are designed for circuit efficiency but struggle on conventional hardware, often orders of magnitude slower than standard hashes due to their reliance on expensive finite field arithmetic. To bridge this performance gap, we present HashEmAll, a novel collection of FPGA-based realizations for three prominent ZK-friendly hashes: Griffin, Rescue-Prime, and Reinforced Concrete. Each offers distinct optimization profiles, with both area-optimized and latency-optimized variants available, allowing users to tailor hardware selection to specific application constraints regarding resource utilization and performance. Our extensive evaluation shows that latency-optimized HashEmAll designs outperform CPU implementations by at least $10 \times$, with the leading design achieving a $23 \times$ speedup. These gains are coupled with lower power consumption and compatibility with accessible FPGAs. Importantly, the highly parallel and pipelined architecture of HashEmAll enables significantly better practical scaling than CPU-based approaches towards building real-world ZKP applications, such as data commitments with Merkle Trees, by mitigating the hashing bottleneck for large trees. This highlights the suitability of HashEmAll for real-world ZKP applications involving large-scale data authentication. We also highlight the ability to translate the HashEmAll methodology to various ZK-friendly hash functions and different field sizes.

Delaram Kahrobaei, Ludovic Perret, Martina Vigorito

Abstract Bidoux and Gaborit introduced a new general technique to improve zero-knowledge ( ZK ) proof-of-knowledge ( PoK ) schemes for a large set of well-known post-quantum hard computational problems such as the syndrome decoding, the permuted kernel, the rank syndrome decoding, and the multivariate quadratic ( MQ ) problems. In particular, the authors’ idea in the study of Bidoux and Gaborit was to use the structure of these problems in the multi-instance setting to minimize the communication complexity of the resulting ZK PoK schemes. The security of the new schemes is then related to new hard problems. In this article, we focus on the new multivariate-based ZK PoK and the corresponding new underlying problem: the so-called <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:msub> <m:mrow> <m:mi mathvariant="monospace">DiffMQ</m:mi> </m:mrow> <m:mrow> <m:mi mathvariant="normal">H</m:mi> </m:mrow> </m:msub> </m:math> {{\mathtt{DiffMQ}}}_{{\rm{H}}} . We present a new efficient probabilistic algorithm for solving the <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:msub> <m:mrow> <m:mi mathvariant="monospace">DiffMQ</m:mi> </m:mrow> <m:mrow> <m:mi mathvariant="normal">H</m:mi> </m:mrow> </m:msub> </m:math> {{\mathtt{DiffMQ}}}_{{\rm{H}}} which is polynomial-time if <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mi>m</m:mi> <m:mo>−</m:mo> <m:mi>n</m:mi> <m:mo>∈</m:mo> <m:mi>O</m:mi> <m:mrow> <m:mo>(</m:mo> <m:mrow> <m:mn>1</m:mn> </m:mrow> <m:mo>)</m:mo> </m:mrow> </m:math> m-n\in O\left(1) . We also present experimental results showing that the algorithm is efficient in practice.

Philippe Gaborit, Mercedes Haiech, Romaric Neveu

At a time when post-quantum cryptography is more and more present in the cryptographic landscape, it is of great interest to find new hard problems on which we can rely. Here, we present a new problem, the vector space factorization problem, and use it to build a signature scheme. The idea of factorizing subspaces of a finite field is used in rank metric codes, most notably in the decoding of LRPCs. In this context, one of the subspaces is known to factorize. Factorizing without the knowledge of both subspaces appears in the signature scheme Murave, in which the rank support basis decomposition problem is introduced from a coding theory in rank metric point of view. In Bro's thesis, the SquareSpace problem is introduced, where one wants to find the 'square root' of a subspace. We generalize here this problem into the vector space factorization problem, which is the same as the rank support basis decomposition problem introduced in Murave, the difference being we do not look at it from a coding theory point of view, but really from a vector subspace one. We use it here to build a zero-knowledge proof of knowledge. The scheme uses the MPCitH paradigm, and especially the TCitH framework, which is an efficient way to build ZK proofs. We study the difficulty of solving the vector space factorization problem by detailing the combinatorial attacks on the problem, analyzing their complexity, and describing an algebraic model to solve the problem. We then explain the MPC protocol used to build the signature scheme. Finally, this construction allows us to obtain sizes of signature of 8.9 to 10.9 kB for the first security level defined by NIST, which is reasonable as MPC-in-the-Head signatures typically range from 2.5 kB for an MQ instance to 14 kB for lattice-based instances.

Hanh Tran Thi, Nghi Nguyen Van, Ngoc Le Anh, Hung Dinh Van

No abstract is available for this record.

I. D. Ioganson, QApp, Vadim Davydov, Jean-Michel Nikodemovich Dakuo · 5 authors

In the paper, a novel isogeny-based protocol for mental poker game is presented. This protocol allows multiple users to create and shuffle a deck of cards, and then issue a card to a specific user. Two versions of the protocol are developed: one without validation, which protects only against passive adversaries, and one with validation, which also allows detecting active interference with the protocol using zero-knowledge proof protocols. To validate the resulting solution, a C program was developed that implements the described protocol. This demonstrates the practical applicability of the proposed solution while ensuring protection against quantum attacks.

Federico Barbacovi, Enrique Larraia, Paul Germouty, Wei Zhang

No abstract is available for this record.

Dung Bui, Kelong Cong, Cyprien Delpech de Saint Guilhem

No abstract is available for this record.

Alisah Ozcan, Arsalan Javeed, Erkay Savaş

The number theoretic transform (NTT) provides a practical and efficient technique to perform multiplication of very large degree polynomials typically found in fully homomorphic encryption (FHE), lattice-based cryptography, and non-interactive succinct zero-knowledge proof systems such as zk-SNARK. In this paper, we focus on this aspect and present two robust algorithms for efficient NTT using readily available GPU cards as hardware accelerators. These algorithms are based on the radix-2 Cooley-Tukey (CT) and 4-Step techniques, which are rooted in classical FFT research. To this end, our algorithms leverage novel strategy to optimize memory access patterns adaptive to input size, which often is very large. Our approach: i) reduces and optimizes the number of accesses required for global memory for thread synchronization on the GPU device, and ii) systematically improves and enhances the use of spatial locality. We achieve this effect by carefully controlling parameters such as the number of kernels, thread block size and shape, and thread layout, which directly impact overall NTT performance. The proposed optimizations enable our NTT implementation to handle very large polynomial sizes up to 228, which are usually a limiting factor in existing approaches, and achieve remarkable performance. To the best of our knowledge, our proposed technique is unique and provides a recipe for selecting suitable configurable parameter combinations to achieve top performance for a given polynomial degree. Furthermore, we perform thorough experiments and empirically assess the performance of our proposed algorithms on three mainstream commercial GPU cards by NVIDIA. Finally, we demonstrate that our algorithms compare favorably and outperform an existing commercial-grade open-source implementation in this arena.

Robin Geelen, Fréderik Vercauteren

No abstract is available for this record.

Joel Poncha Lemayian, Ghyslain Gagnon, Kaiwen Zhang, Pascal Giard

ABSTRACT Cryptocurrency blockchain networks safeguard digital assets using cryptographic keys, with wallets playing a critical role in generating, storing, and managing these keys. Wallets, typically categorized as hot and cold, offer varying degrees of security and convenience. However, they are generally software‐based applications running on microcontrollers. Consequently, they are vulnerable to malware and side‐channel attacks, allowing perpetrators to extract private keys by targeting critical algorithms, such as ECC, which processes private keys to generate public keys and authorize transactions. To address these issues, this work presents EthVault, the first hardware architecture for an Ethereum hierarchically deterministic cold wallet, featuring hardware implementations of key algorithms for secure key generation. Also, an ECC architecture resilient to side‐channel and timing attacks is proposed. Moreover, an architecture of the child key derivation function, a fundamental component of cryptocurrency wallets, is proposed. The design minimizes resource usage, meeting market demand for small, portable cryptocurrency wallets. FPGA implementation results validate the feasibility of the proposed approach. The ECC architecture exhibits uniform execution behavior across varying inputs, while the complete design utilizes only 27%, 7%, and 6% of LUTs, registers, and RAM blocks, respectively, on a Xilinx Zynq UltraScale+ FPGA.

Shi Wang

Traditional identity authentication algorithms that rely on centralized trust authorities and plaintext identity verification often suffer from privacy leakage, key misuse, and single-point-of-failure risks. This study proposes a lightweight, privacy-preserving authentication algorithm based on elliptic curve and zero-knowledge proofs to address these issues. The proposed scheme introduces a random challenge and an anonymous verification mechanism during the authentication process to ensure both identity privacy and authentication security. While maintaining high levels of security and verifiability, the algorithm effectively reduces computational complexity and communication overhead. Experimental results demonstrate that the proposed method significantly outperforms traditional RSA and ECDSA in terms of authentication delay, communication cost, and security robustness. This approach is practical and scalable, offering a promising solution for secure authentication in environments with limited resource.