Yuanfeng Xie, Weiwei Jiang, Hanqing Luo, Jian Ping Gan
This study presents an innovative authentication scheme that integrates Physical Unclonable Functions (PUFs) and Zero-Knowledge Proofs (ZKP) to provide efficient and secure authentication for Internet of Things (IoT) devices. Traditional PUF-based protocols offer strong security but incur high resource costs and slow authentication. To address this, we propose a joint scheme. First, a unified architecture combining a PUF–True Random Number Generator (TRNG) is introduced. This architecture utilizes a feedback permutation obfuscation mechanism and an arbitration delay deviation with a metastable design from a ring oscillator, ensuring the PUF–TRNG system possesses both attack resistance and true random properties. The architecture provides synchronization for both PUF and TRNG in the protocol. Next, we integrate Schnorr’s ZKP with a PUF-based key encapsulation and reconstruction scheme to construct an end-to-end anonymous identity authentication protocol that does not require real-time participation of a trusted third party. The protocol requires only two handshakes, significantly reducing the number of protocol rounds compared to related protocols. Finally, the PUF–TRNG architecture has been implemented on the Xilinx XC7A100T development board. Experimental results show that the PUF circuit effectively resists various modeling attacks. Formal verification with ProVerif demonstrates confidentiality, mutual authentication, and robustness against mainstream attacks. The protocol reduces area overhead and computational time by 43.04% and 42.99%, respectively, compared to similar protocols.
Physical Unclonable Functions (PUFs) and Hardware Security
The rapid progress of quantum computing poses significant challenges to traditional cryptographic mechanisms, necessitating the adoption of post-quantum cryptography (PQC) solutions. This paper proposes a Quantum-Enhanced Security for Smart Meters (QESM) system to protect power plant data in smart cities, integrating Kyber for secure key exchange, FALCON (Fast-Fourier Transform over Lattice-based Cryptography) for quantum-resistant digital signatures, and ZKP (Zero-Knowledge Proof) for effective verification without revealing sensitive data to secure power plant data against quantum attacks. To evaluate the security of the proposed system, we analyze its resistance to various quantum threats, including Shor’s algorithm, Grover’s algorithm, quantum key analysis, quantum reversal encryption, quantum amplification, quantum switching, and quantum collision attacks. In the current study, accurate measures were used and the average was approximately 7.065 (bits/byte) for randomness, the average execution time was 6.202 milliseconds, the average memory consumption was approximately 4.343 KB, 6.4 Completeness was equal to 1 and unforgeability was 100%. As for the average throughput, it was approximately 485,605 operations per second. That shows the QESM system provides strong security and efficiency, making it a viable solution for protecting the electricity infrastructure in smart cities in the quantum era.
Privacy in blockchain-based cryptocurrencies has become a critical area of research and development. This is driven by the transparent nature of public ledgers and the growing demand for confidential transactions. This study provides a comprehensive exposition of a prominent privacyenhancing protocol, Zcash. We begin by elucidating the design and operation of Tornado Cash, a smart contract-based mixer on Ethereum that leverages zero-knowledge proofs to enable unlinkable transactions. Building on this foundation, we explore the Zcash protocol, tracking its evolution from Bitcoin and its innovative use of zk-SNARKs. We also examine the intricate mechanisms that highlight its privacy guarantees, including circuit design, Merkle tree structures and transaction relations. By systematically analyzing and comparing these protocols, this study aims to clarify their inner workings, highlight their strengths and limitations, and provide information on the future of privacy in decentralized finance.
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 pro les, 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×, with the leading design achieving a 23× 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.
Alison Gonçalves Schemitt, Henrique Fan da Silva, Roben Castagna Lunardi, Diego Kreutz · 6 authors
The advent of quantum computing poses a threat to the security of traditional encryption algorithms. This has motivated the development of post-quantum cryptography (PQC). In 2024, the National Institute of Standards and Technology (NIST) standardized several PQC algorithms, marking an important milestone in the transition toward quantum-resistant security. Blockchain systems fundamentally rely on cryptographic primitives to guarantee data integrity and transaction authenticity. However, widely used algorithms such as ECDSA, employed in Bitcoin, Ethereum, and other networks, are vulnerable to quantum attacks. Although adopting PQC is essential for long-term security, its computational overhead in blockchain environments remains largely unexplored. In this work, we propose a methodology for benchmarking both PQC and traditional cryptographic algorithms in blockchain contexts. We measure signature generation and verification times across diverse computational environments and simulate their impact at scale. Our evaluation focuses on PQC digital signature schemes (ML-DSA, Dilithium, Falcon, Mayo, SLH-DSA, SPHINCS+, and Cross) across security levels 1 to 5, comparing them to ECDSA, the current standard in Bitcoin and Ethereum. Our results indicate that PQC algorithms introduce only minor performance overhead at security level 1, while in some scenarios they significantly outperform ECDSA at higher security levels. For instance, ML-DSA achieves a verification time of 0.14 ms on an ARM-based laptop at level 5, compared to 0.88 ms for ECDSA. We also provide an open-source implementation to ensure reproducibility and to encourage further research.
Zero-knowledge proofs (ZKPs) are increasingly adopted in practical cryptographic systems, yet zkSNARK generation remains computationally expensive, limiting scalability. Recent distributed zkSNARK frameworks, such as zkSaaS and Siniel, mitigate this cost by partitioning witnesses across multiple workers. However, they often depend on heavy MPC interactions and full verifier-side proof checking, which hinders their usability in asynchronous or large-scale settings. We present CoVer, a novel distributed zkSNARK system over binary fields, optimized for hardware-level parallelism. CoVer introduces a verifier-guided VOLE-based challenge mechanism that enforces global constraint consistency across subproofs while removing multi-round MPC and tag consistency checks. This design reduces communication and prevents challenge manipulation. Experiments show CoVer achieves up to$150 \times$verification efficiency improvement under variable bandwidth conditions.
In recent years, zero-knowledge proofs have made great strides in efficiency, on two fronts: minimizing the finite field size without sacrificing security and allowing more constructs in their intermediate representations, such as look-ups. These have lead to novel, efficiently aritmetizable, hash functions, which are the backbone of modern proof systems. We take advantage of these improvements and present a resource constrained hardware design for the Monolith hash function, targeted torwards embedded, edge IoT devices. The hardware implementation demonstrates a significant performance advantage over the software-only solution on the Zynq SoC, achieving a 22× speed-up while consuming only a few hundred milliwatts.
Cryptographic Implementations and Security
Cryptography and Residue Arithmetic
Physical Unclonable Functions (PUFs) and Hardware Security
Zero-knowledge proof (ZKP) applications require translating high-level programs into arithmetic circuits–a process that demands both correctness and efficiency. While recent DSLs improve usability, they often yield suboptimal circuits, and hand-optimized implementations remain difficult to construct and verify. We present Tabby, a synthesis-aided compiler that automates the generation of high-performance ZK circuits from highlevel code. Tabby introduces a domain-specific intermediate representation designed for symbolic reasoning and applies sketch-based program synthesis to derive optimized low-level implementations. By decomposing programs into reusable components and verifying semantic equivalence via SMT-based reasoning, Tabby ensures correctness while achieving substantial performance improvements. We evaluate Tabby on a suite of real-world ZKP applications and demonstrate significant reductions in proof generation time and circuit size against mainstream ZK compilers.
Nayantara Thomas, Liya Treesa Philip, Pampana Jahnavi, R. Sujatha · 5 authors
The increasing complexity and globalization of the semiconductor supply chain, particularly in Field-Programmable Gate Arrays (FPGAs), has introduced significant vulnerabilities including counterfeiting, unauthorized modifications, and malicious hardware insertions. To address these challenges, this project proposes a novel security framework that integrates Zero Trust Architecture (ZTA), blockchain technology, and Arbiter Physical Unclonable Functions (PUFs) to enhance the authenticity, traceability, and resilience of the FPGA supply chain. The framework employs PUFs to generate unique hardware identities for FPGA components, which are authenticated through smart contracts and immutably recorded on a permissioned blockchain. By adopting ZTA principles, the system ensures continuous verification of all entities and components across the supply chain. The proposed architecture supports real-time monitoring, automated anomaly detection, and role-based access control, creating a tamper-proof and transparent ledger of FPGA transactions. This approach significantly strengthens supply chain integrity, mitigates risks of counterfeit insertion, and establishes a secure foundation for deploying FPGAs in mission-critical applications such as defense, telecommunications, and AI systems.
Physical Unclonable Functions (PUFs) and Hardware Security
The article presents a comprehensive overview of zero-knowledge proof (ZKP) protocols as a fundamental concept of modern cryptography. The historical background of their emergence and the main properties ensuring reliability and confidentiality, i.e., completeness, soundness, and zero-knowledge — are considered. A classification of protocols into interactive and non-interactive ones is provided, with a special focus on modern solutions such as the zk-SNARK and the zk-STARK. The mathematical foundations of ZKPs are described in detail, including discrete logarithm proofs, the use of homomorphic encryption, polynomial commitments, hashing, and elliptic curves. Practical application areas are analyzed, including cryptocurrencies (Zcash, Ethereum), authentication systems, digital identity, and electronic voting. The advantages of using ZKPs are shown, such as enhanced privacy, reduced need for trusted intermediaries, and strengthened security. At the same time, key challenges are outlined, including scalability, implementation complexity, the problem of trusted setup, and potential vulnerability to quantum computing. It is concluded that zero-knowledge proof protocols are a powerful tool for ensuring confidentiality and reliability of digital systems, while further research is aimed at creating more efficient and quantum-resistant solutions.
ChipmunkRing, a practical post-quantum ring signature construction tailored for blockchain environments. Building on our Chipmunk lattice-based cryptographic framework, this implementation delivers compact digital signatures ranging from 20.5 to 279.7KB, with rapid signing operations completing in 1.1-15.1ms and efficient validation processes requiring only 0.4-4.5ms for participant groups of 2-64 members. The cornerstone of our approach is Acorn Verification-a streamlined zero-knowledge protocol that supersedes the classical Fiat-Shamir methodology. This innovation enables linear O(n) authentication complexity using concise 96-byte cryptographic proofs per participant, yielding a remarkable 17.7x performance enhancement for 32-member rings when compared to conventional techniques. Our work includes rigorous mathematical security demonstrations confirming 112-bit post-quantum protection (NIST Level 1), extensive computational benchmarking, and comprehensive support for both standard anonymity sets and collaborative threshold constructions with flexible participation requirements.
Ryota Takenouchi, Haruki Kurisaka, Yue Su, Kien Nguyen · 5 authors
As quantum computing threatens the security of traditional cryptographic algorithms used in blockchain systems, integrating post-quantum cryptography (PQC) into IoT-blockchain environments has become a critical research direction. However, the practicality of PQC in resource-constrained IoT devices remains largely unexplored. This paper presents a fully operational IoT-blockchain system that concurrently runs PQC algorithms and blockchain processes on Raspberry Pi 4 nodes using Ethereum and Proof-of-Stake consensus. We implement and evaluate three NIST-recommended PQC algorithms (i.e., Dilithium, FALCON, and SPHINCS+) and assess their impact on CPU utilization, memory and disk usage, and power consumption. The results show that SPHINCS+ introduces significant overhead due to its hash-based signature scheme, whereas Dilithium and FALCON have minimal performance impact and are more suitable for constrained environments. All PQC algorithms, however, lead to a notable increase in disk usage. This study provides the first system-level evaluation of PQC-integrated IoT-blockchain platforms and offers practical insights for secure and efficient deployment in the post-quantum era.
Conventional cryptographic approaches face increasing insecurity because quantum computing and attacks enabled by AI operate at a rapid speed of technological advancement. The review analyzes IEEE research activities on progressive cryptographic methods consisting of post-quantum cryptography (PQC) and fully homomorphic encryption (FHE) in addition to zero-knowledge proofs (ZKP) and AI-augmented cryptographic models. We explore both advantages and limitations in addition to applicable uses for protecting modern digital frameworks which include blockchain, IoT and 5G networks. Standardization efforts as well as hybrid crypto framework trends receive analysis in the article to establish long-lasting secure systems.
Side-channel attacks pose significant threats to cryptographic implementations, which require the inclusion of countermeasures to mitigate these attacks. In this work, we study the masking of state-of-the-art post-quantum signatures based on the MPC-in-the-head paradigm. More precisely, we focus on the recent threshold-computation-in-the-head (TCitH) framework that applies to some NIST candidates of the post-quantum standardization process. We first provide an analysis of side-channel attack paths in the signature algorithms based on the TCitH framework. We then explain how to apply standard masking to achieve a d-probing secure implementation of such schemes, with performance scaling in O(d2), for d the masking order.Our main contribution is to introduce different ways to tweak those signature schemes towards their masking friendliness. While the TCitH framework comes in two variants, the GGM variant and the Merkle tree variant, we introduce a specific tweak for each of these variants. These tweaks allow us to achieve complexities of O(d) and O(d log d) at the cost of non-constant signature size, caused by the inclusion of additional seeds in the signature. We also propose a third tweak that takes advantage of the threshold secret sharing used in TCitH. With the right choice of parameters, we show how, by design, some parts of the TCitH algorithms satisfy probing security without additional countermeasures. While this approach can substantially reduce the cost of masking in some part of the signature algorithm, it degrades the soundness of the core zero-knowledge proof, hence slightly increasing the size of the signature.We analyze the complexity of the masked implementations of our tweaked TCitH signatures and provide benchmarks on a RISC-V platform with built-in hash accelerator. We use a modular benchmarking approach, allowing to estimate the performance of diverse signature instances with different tweaks and parameters. Our results illustrate how the different variants scale for an increasing masking order. For instance, for a masking order d = 3, we obtain signatures of around 14 kB that run in 0.67 second on a the target RISC-V CPU with a 250MHz frequency. This is to be compared with the 4.7 seconds required by the original signature scheme masked at the same order on the same platform. For a masking order d = 7, we obtain a signature of 17.5 kB running in 1.75 second, to be compared with 16 seconds for the stardard masked signature.Finally, we discuss the extension of our techniques to signature schemes based on the VOLE-in-the-Head framework, which shares similarities with the GGM variant of TCitH. One key takeaway of our work is that the Merkle tree variant of TCitH is inherently more amenable to efficient masking than frameworks based on GGM trees, such as TCitH-GGM or VOLE-in-the-Head.
Florian Hirner, Florian Krieger, Constantin Piber, Sujoy Sinha Roy
Zero-knowledge proofs (ZKPs) are cryptographic protocols that enable one party to prove the validity of a statement without revealing any information beyond its truth. Central building blocks in many ZKPs are polynomial commitment schemes (PCS) where constructions with linear-time provers are especially attractive. Two such examples are Brakedown and its extension Orion, which enable linear-time and quantum-resistant proving by leveraging linear-time encodable Spielman codes. However, these PCS operate over large datasets, creating significant computational bottlenecks. For example, committing to and proving a degree 228 polynomial requires around 1.1 GB of data while taking 463 seconds on a high-end server CPU.This work addresses the performance bottleneck in Orion-like PCS by optimizing their most critical operations: Spielman encoding and Merkle commitments. These operations involve Gigabytes of data and suffer from random off-chip memory access patterns that drastically reduce off-chip bandwidth. We resolve this issue and introduce inverted expander graphs to eliminate random writes and reduce off-chip memory accesses by over 50%. Additionally, we propose an on-the-fly graph sampling method that avoids streaming large auxiliary data by generating expander graphs dynamically on-chip. We also provide a formal security proof for our proposed graph transformation. Beyond encoding, we accelerate Merkle Tree construction over large data sets through a scalable multi-pass SHA3 pipeline. Finally, we reutilize existing hardware components used in commitment to accelerate the so-called proximity and consistency checks during proof generation.Building upon these concepts, we present the first hardware architecture for PCS – with linear prover time – on an Xilinx Alveo U280 FPGA. In addition, we discuss the practical challenges of manually partitioning, placing, and routing our large-scale architecture to efficiently map it to the multi-SLR and HBM-equipped FPGA. The final implementation achieves a speedup of two orders of magnitude for full proof generation, covering commitment and proving steps. When combined with Virgo as an outer CP-SNARK protocol, our accelerator reduces end-to-end latency by up to 3.85x – close to the theoretical maximum of 3.9x.
The rapid expansion of Internet of Things (IoT) deployments across smart environments introduces critical security challenges, particularly at the device identity and physical layers. Traditional cryptographic methods and Distributed Ledger Technologies (DLTs), while valuable, often fail to account for the constrained resources of IoT devices and their susceptibility to physical-layer attacks. This paper proposes a scalable, lightweight security framework that integrates Physical Unclonable Functions (PUFs), Zero-Knowledge Proofs (ZKPs), and a permissioned blockchain to establish end-to-end trust in distributed IoT ecosystems. PUFs act as hardware-rooted trust anchors, enabling secure key generation and unclonable device identity without relying on non-volatile memory. ZKPs facilitate mutual authentication by allowing devices to prove legitimacy without revealing any identifying information. A permissioned blockchain acts as a decentralised verification and audit layer, immutably recording authentication events and ensuring tamper resistance with controlled governance. The proposed architecture is designed to counteract physical tampering, spoofing, and identity forgery while remaining computationally viable for resource-constrained IoT devices. This work presents the foundation for a robust, privacy-preserving, and decentralised security model, bridging the gap between hardware-level assurance and scalable trust in future IoT deployments.
Physical Unclonable Functions (PUFs) and Hardware Security
Bruno M. F. Ricardo, Lucas C. Cardoso, Leonardo T. Kimura, Marcos A. SimplÃcio · 5 authors
In 2023, Barreto and Zanon proposed a three-round Schnorr-like blind signature scheme, leveraging zero-knowledge proofs to produce one-time signatures as an intermediate step of the protocol. The resulting scheme, called BZ, is proven secure in the discrete-logarithm setting under the one-more discrete logarithm assumption with (allegedly) resistance to the Random inhomogeneities in a Overdetermined Solvable system of linear equations modulo a prime number p attack, commonly referred to as ROS attack. The authors argue that the scheme is resistant against a ROS-based attack by building an adversary whose success depends on extracting the discrete logarithm of the intermediate signing key. In this paper, however, we describe a distinct ROS attack on the BZ scheme, in which a probabilistic polynomial-time attacker can bypass the zero-knowledge proof step to break the one-more unforgeability of the scheme. We also built a BZ variant that, by using one secure hash function instead of two, can prevent this particular attack. Unfortunately, though, we show yet another ROS attack that leverages the BZ scheme’s structure to break the one-more unforgeability principle again, thus revealing that this variant is also vulnerable. These results indicate that, like other Schnorr-based strategies, it is hard to build a secure blind signature scheme using BZ’s underlying structure.
Emerging applications in cloud computing, big data, and the Internet of things have driven the advancement and implementation of security protocols, including secure multi-party computation, fully homomorphic encryption, and zero-knowledge proofs, to meet heightened security demands. Designing cryptographic permutations and block ciphers using a partial substitution-permutation network (P-SPN) approach, where the nonlinear part does not cover the entire state, has recently gained attention due to favorable implementation characteristics in various scenarios. For the word-oriented P-SPN schemes with a fixed linear layer, the choice of the maximum distance separable (MDS) matrix significantly affects the security level provided by P-SPN designs. If the MDS matrix is chosen weak, it will allow for extremely maximum invariant subspace that pass the entire rounds without activating any non-linear operation. Firstly, we investigate the properties of a special block matrix with circulant block, specifically utilized within the linear layer matrix of P-SPN structure schemes. Subsequently, our investigation extends to present the annihilating polynomial of low degree for these specific type of matrices, as well as to put forward the range of determining their minimal polynomial degree. Finally, this study articulates a lower bound estimated for the dimension of the maximum invariant subspace within the P-SPN structure schemes when integrated with the aforementioned matrix type. In scenarios where the S-box number$s$= 1 in the P-SPN structure schemes, we achieve a precise determination of the dimension of maximum invariant subspace. Conversely, for cases with$s$> 1, with some certain specific conditions, our research establishes more compact lower bound for the dimension of the maximum invariant subspace. The research results of this paper offer valuable design guidance for the development of matrices within the linear layer of P-SPN architecture schemes.
This paper studies the practical aspects of adding zero-knowledge proofs of vote correctness to Internet voting, specifically to the IVXV system used in Estonia. We discuss various available alternatives and present a concrete instantiation based on Bulletproofs together with implementation details and benchmarking results. As IVXV currently uses the ElGamal cryptosystem with a 3072-bit prime modulus for vote encryption, but Bulletproofs work most efficiently on elliptic curves, a group switching solution is also implemented and benchmarked. Despite all the extra work required, our solution is very performant and well capable of sustaining the load of votes, even during peak vote submission periods.
The rapid advancement of quantum computing poses significant challenges to conventional cryptography, necessitating the adoption of post-quantum cryptography (PQC) solutions. This chapter proposes a Post-Quantum Lattice Security (PQLS) system for protecting power plant data in smart cities. It integrates Kyber for secure key exchange, Falcon for quantum-resistant digital signatures, ZKP for efficient authentication without revealing sensitive data, and JSON-LD for standardizing the format of data received from different smart meters. To evaluate the security of the proposed framework, we analyze its resistance to various threats, such as side-channel and message recovery attacks. We measured key performance indicators. The results showed an average CPU utilization of 2.4592 MS, memory consumption averaging 1843.899 KB, an execution time of 2.45 MS, and a level averaging 66.27677. This demonstrates that our proposed system offers high security and efficiency, making it a practical solution for protecting electrical infrastructure in smart cities in the quantum era.