This research focuses on implementing the Zero-Knowledge Proof (ZKP) protocol as part of IoT systems, specifically within smart home environments. The system relies on the WISE protocol for communication between physical devices and the central controller. As the system evolved, the optimization concept led to migrating the central controller’s logic to the cloud. In the latest development phase, the cloud-based central controller is utilized for data processing and analysis, leveraging the WISE protocol’s features for efficient data collection from both applications and devices. As an example of a physical device, set-top boxes are utilized for real-time transmission of critical logs for diagnostic purposes. Additionally, the WISE client enables continuous log and data collection from applications, initiating upon application initialization. This capability allows the WISE client to monitor and document potential issues or irregularities in real-time application operation. The implementation of the ZKP protocol on the cloud-based central controller facilitates secure and private communication between devices and the data collection system, without compromising sensitive information. This research explores the application of the ZKP protocol concerning the utilization of physical or logical devices within systems based on the WISE protocol, providing a secure and efficient solution for device-to-central system communication in the cloud.
Joel Sousa, Emerson B. Tomaz, Allysson Allex Araújo
Authenticity represents an essential facet of information security explored across various Information Systems (IS), including Internet of Things (IoT) devices in Industry 4.0. However, deploying authentication mechanisms in specific IoT devices poses significant challenges, particularly for those with energy, memory, and computational power constraints. Given this context, this ongoing research project aims to compare conventional authentication mechanisms for low-resource IoT devices and identify the most efficient one among them. As an initial result, this paper aims to present our methodological scope and discuss preliminary empirical results derived from a computational experiment using the Non Interactive Zero Knowledge Proofs (NIZKP), algorithm in Arduino Nano. This research seeks to enhance the comprehension of authentication mechanisms in low-resource IoT devices, thus facilitating better decision-making processes in IS settings and contributing to academia and practice.
Marco Stronati, Denis Firsov, Antonio Locascio, Benjamin Livshits
Plonkish is a popular circuit format for developing zero-knowledge proof systems that powers a number of major projects in the blockchain space, responsible for holding billions of dollars and processing millions of transactions per day. These projects, including zero-knowledge rollups, rely on highly hand-optimized circuits whose correctness comes at the cost of time-consuming testing and auditing. In this paper, we present Clap, the first Rust eDSL with a proof system agnostic circuit format, facilitating extensibility, automatic optimizations, and formal assurances for the resultant constraint system. Clap casts the problem of producing Plonkish constraint systems and their witness generators as a semantic-preserving compilation problem. Soundness and completeness of the transformation guarantees the absence of subtle bugs caused by under- or over-constraining. Our experimental evaluation shows that its automatic optimizations achieve better performance compared to manual circuit optimization. The optimizer can also be used to automatically derive custom gates from circuit descriptions.
Domain-specific knowledge can significantly contribute to addressing a wide variety of vision tasks. However, the generation of such knowledge entails considerable human labor and time costs. This study investigates the potential of Large Language Models (LLMs) in generating and providing domain-specific information through semantic embeddings. To achieve this, an LLM is integrated into a pipeline that utilizes Knowledge Graphs and pre-trained semantic vectors in the context of the Vision-based Zero-shot Object State Classification task. We thoroughly examine the behavior of the LLM through an extensive ablation study. Our findings reveal that the integration of LLM-based embeddings, in combination with general-purpose pre-trained embeddings, leads to substantial performance improvements. Drawing insights from this ablation study, we conduct a comparative analysis against competing models, thereby highlighting the state-of-the-art performance achieved by the proposed approach.
This paper presents a framework for securing blockchain-based IoT systems by integrating Physical Unclonable Functions (PUFs) and Zero-Knowledge Proofs (ZKPs) within a Hyperledger Fabric environment. Our approach leverages PUFs for robust device authentication and ZKPs for privacy-preserving transaction processing, addressing key challenges of security, privacy, and scalability in IoT systems. The framework’s architecture utilizes Hyperledger Fabric’s modular design and private channels to enhance scalability. Off-chain experimental results demonstrate the framework’s feasibility, with compact proof sizes (median 805 bytes) and efficient processing times (average 2,800 ms end-to-end). A comprehensive security analysis shows the framework’s resilience against various attacks, including device impersonation and data tampering. This work provides a foundation for secure and scalable blockchain-based IoT systems, with directions for future on-chain implementation and optimization for resource-constrained devices.
Open access
3 source records
Blockchain Technology Applications and Security
Physical Unclonable Functions (PUFs) and Hardware Security
Advanced Steganography and Watermarking Techniques
Inner product arguments (IPA) are arguments of knowledge that two committed vectors satisfy an inner product relation. With the recursive proof technique by Bootle et al. 2016, the size of IPA proofs only grows logarithmically in the length of the vectors, without a trusted setup. The succinct proof makes IPAs well suited for blockchain applications. However, current IPA can only handle a vector with length a power of 2, which limits the application of the argument. One direct solution is to pad the vectors with zeros, which incurs additional overhead. We propose Springproofs, a new framework deriving IPAs from many existing IPA schemes. Springproofs are natively compatible with vectors of arbitrary length. With a novel recursive compression structure, Springproofs achieve the same proof size as the original IPA but with more efficient computation. In particular, we instantiate Springproofs with Bulletproofs and find the optimal recursive structure for the IPA. First, we experimentally show that Springproofs are almost twice as fast as Bulletproofs for range proof, when the vector length is slightly larger than a power of 2. Afterwards, we incorporate the Springproofs into Monero, a popular cryptocurrency supporting privacy in transactions, revealing that the Springproofs based Monero outperforms Bulletproofs based Monero both in generating and verifying transactions. Moreover, we apply the Springproofs to the general arithmetic circuit, including SHA256, Merkle tree, and typical statistics, the performances on which are better than the performances by using Bulletproofs. Interestingly, Springproofs increase the range of parameters on which the performance of Bulletproofs exceeds that of Groth16, meanwhile naturally inherit the advantages of Bulletproofs, e.g., without initial trusted setup, aggregation, and batch verification. As a result, Springproofs have many promising applications, including confidential transactions in cryptocurrency and privacy computing for specific arithmetic circuits in smart contracts.
Anonymous Zether, proposed by Bünz et al. (FC, 2020) and subsequently improved by Diamond (IEEE S&P, 2021) is an account-based confidential payment mechanism that works by using a smart contract to achieve privacy (i.e. identity of receivers to transactions and payloads are hidden). In this work, we look at simplifying the existing protocol while also achieving batching of transactions for multiple receivers, while ensuring consensus and forward secrecy. To the best of our knowledge, this work is the first to formally study the notion of forward secrecy in the setting of blockchain, borrowing a very popular and useful idea from the world of secure messaging. Specifically, we introduce:•FUL-Zether, a forward-secure version of Zether (Bünz et al. , FC, 2020),•PRIvate DEcentralized Confidential Transactions (PriDe CT), a much-simplified version of Anonymous Zether that achieves competitive performance and enables batching of transactions for multiple receivers.•PRIvate DEcentralized Forward-secure Until Last update Confidential Transactions (PriDeFUL CT), a forward-secure version of PriDe CT.We also present an open-source, Ethereum-based implementation of our system. PriDe CT uses linear homomor-phic encryption as Anonymous Zether but with simpler zero-knowledge proofs. PriDeFUL CT uses an updatable public key encryption scheme to achieve forward secrecy by introducing a new DDH-based construction in the standard model.In terms of transaction sizes, Quisquis (Asiacrypt, 2019), which is the only cryptocurrency that supports batchability (albeit in the UTXO model), has 15 times more group elements than PriDe CT. Meanwhile, for a ring of N receivers, Anonymous Zether requires 6 log N more terms even without accounting for the ability to batch in PriDe CT. Further, our implementation indicates that, for N = 32, even if there were 7 intended receivers, PriDe CT outperforms Anonymous Zether in proving time and gas consumption.
Weihao Bai, Long Chen, Qianwen Gao, Zhenfeng Zhang
The MPC-in-the-Head framework has been proposed as a solution for Non-Interactive Zero-Knowledge Arguments of Knowledge (NIZKAoK) due to its efficient proof generation. However, most existing NIZKAoK constructions using this approach require multiple MPC evaluations to achieve negligible soundness error, resulting in proof size and time that are asymptotically at least λ times the size of the circuit of the NP relation. In this paper, we propose a novel method to eliminate the need for repeated MPC evaluations, resulting in a NIZKAoK protocol for any NP relation that we call Diet. The proof size and time of Diet are asymptotically only polylogarithmic with respect to the size of the circuit C of the NP relation, but are independent of the security parameter λ. Hence, both the proof size and time can be significantly reduced.Moreover, Diet offers promising concrete efficiency for proving Learning With Errors (LWE) problems and its variants. Our solution provides significant advantages over other schemes in terms of both proof size and proof time, when considering both factors together. Specifically, Diet is a promising method for proving knowledge of secret keys for lattice-based key encapsulation mechanisms (KEMs) such as Frodo and Kyber, offering a practical solution to future post-quantum certificate management. For Kyber 512, our implementation achieves an online proof size of 83.65 kilobytes (KB) with a preprocessing overhead of 152.02KB. The implementation is highly efficient, with an online proof time of only 0.68 seconds and a preprocessing time of 0.81 seconds. Notably, our approach provides the first reported implementation of proving knowledge of secret keys for Kyber 512 using post-quantum primitives-based zero-knowledge proofs.
Borui Gong, Wang Fat Lau, Man Ho Au, Rupeng Yang · 6 authors
We present an efficient zero-knowledge argument of knowledge system customized for the Paillier cryptosystem. Our system enjoys sublinear proof size, low verification cost, and acceptable proof generation effort, while also supporting batch proof generation/verification. Existing works specialized for Paillier cryptosystem feature linear proof size and verification time. Using existing sublinear argument systems for generic statements (e.g., zk-SNARK) results in unaffordable proof generation cost since it involves translating the relations to be proven into an inhibitive large Boolean or arithmetic circuit over a prime order field. Our system does not suffer from these limitations.The core of our argument systems is a constraint system defined over the ring of residue classes modulo a composite number, together with novel techniques tailored for arguing binary values in this setting. We then adapt the approach from Bootle et al. (EUROCRYPT 2016) to compile the constraint system into a sublinear argument system. Our constraint system is generic and can be used to express typical relations in Paillier cryptosystems including range proof, correctness proof, relationships between bits of plaintext, relationships of plaintexts among multiple ciphertexts, and more. Our argument supports batch proof generation and verification, with the amortized cost outperforming state-of-the-art protocol specialized for Paillier when the number of Paillier ciphertext is in the order of hundreds.We report an end-to-end prototype and conduct comprehensive experiments across multiple scenarios. Scenario 1 is Paillier with packing. When we pack 25.6K bits into 400 ciphertexts, a proof that all these ciphertexts are correctly computed is 17 times smaller and is 3 times faster to verify compared with the naive implementation: using 25.6K OR-proofs without packing. Furthermore, we can prove additional statements almost for free, e.g., one can prove that the sum of a subset of the witness bits is less than a threshold t. Another scenario is range proof. To prove that each plaintext in 200 Paillier ciphertexts is of size 256 bits, our proof size is 10 times smaller than the state-of-the-art. Our analysis suggests that our system is asymptotically more efficient than existing protocols, and is highly suitable for scenarios involving a large number (more than 100) of Paillier ciphertexts, which is often the case for data analytics applications.
Zero-knowledge range proofs play a critical role in confidential transactions (CT) on blockchain systems. They are used to prove the non-negativity of committed transaction payments without disclosing the exact values. Logarithmicsized range proofs with transparent setups, e.g., Bulletproofs, which aim to prove a committed value lies in the range [0, 2 -1] where is the bit length of the range, have gained growing popularity for communication-critical blockchain systems as they increase scalability by allowing a block to accommodate more transactions. In this paper, we propose SwiftRange, a new type of logarithmic-sized zero-knowledge range argument with a transparent setup in the discrete logarithm setting. Our argument can be a drop-in replacement for range proofs in blockchain-based confidential transactions. Compared with Bulletproofs, our argument has higher computational efficiency and lower round complexity while incurring comparable communication overheads for CT-friendly ranges, where N ∈ {32, 64}. Specifically, a single SwiftRange achieves 1.73× and 1.37× proving efficiency with no more than 1.1× communication costs for both ranges, respectively. More importantly, our argument is doubly efficient in verification efficiency. Furthermore, our argument has a smaller size when N ≤ 16, making it competitive for many other communication-critical applications. Our argument supports the aggregation of multiple single arguments for greater efficiency in communication and verification. Finally, we benchmarked our argument against the state-of-the-art range proofs to demonstrate its practicality.
Miguel Isabel, Clara Rodríguez-Núñez, Albert Rubio
The application of Zero-Knowledge (ZK) proofs is rapidly growing in the industry and has become a key element to enable privacy and enhance scalability in public distributed ledgers. In most practical ZK systems, the statement to be proven is expressed by means of a set of polynomial equations in a prime field that describe an arithmetic circuit. Describing general statements using this kind of constraints is a complex and error-prone task. This can be partly mitigated by using high-level programming languages, but at the cost of losing control over the added constraints and, as a result, obtaining too large systems for complex statements. In this context, having tools to automatically verify properties of the constraint systems is of paramount importance to guarantee the security of the protocol. However, since non-linear polynomial reasoning over a finite field is needed for checking challenging properties, existing automatic tools either do not scale or cannot detect non-trivial bugs. In this paper, we present a new scalable modular technique based on the application of transformation and deduction rules that have proven to be very effective in verifying properties over the signals of a circuit given as a set of polynomial equations in a large prime field. Our technique has been implemented in a tool called CIVER and applied to verify safety properties for circuits implemented in circom, which is one of the most popular languages for defining ZK protocols. We have been able to analyze large industrial circuits and detect subtle vulnerabilities in circuits designed by expert programmers.
Zero-Knowledge (ZK) proofs were introduced in the seminal work of Goldwasser, Micali, and Rackoff (STOC 1985) and remain one of the cornerstones of modern cryptography. With the advent of Blockchains, there has been reinvigorated interest in deploying ZK-proof systems in the form of ZK-SNARKs. ZKSNARKs are an attractive variant as they are non-interactive (in fact, publicly verifiable) and succinct. Yet, current deployments require huge running times and/or very large memory, and scaling them to large circuits cannot be accomplished on commodity hardware. We design and implement an efficient sublinear non-interactive zero-knowledge system, Ligetron that can be deployed as a web application and scales to billions of gates. Core to our construction is identifying a good intermediate representation, namely Web Assembly (WASM) that is: (1) versatile to represent complex computations, (2) can be compiled from most popular high-level languages, and (3) embodies rich semantics to derive space-efficiency. On the backend, we design and implement a space-efficient variant of the Ligero ZK system introduced in the work of Ames et al. (ACM CCS 2017) that can leverage the semantics of WASM. Ligetron is the first post-quantum ZK-SNARK to scale to billion gates and run from a browser. On commodity hardware, Ligetron scales to arbitrarily large circuits while showcasing competitive prover/verifier running times and better proof lengths than all previous post-quantum ZK-SNARKs.
Tianyi Liu, Tiancheng Xie, Jiaheng Zhang, Dawn Song · 5 authors
In the past decade, blockchains have seen various financial and technological innovations, with cryptocurrencies reaching a market cap of over 1 trillion dollars. However, scalability is one of the key issues hindering the deployment of blockchains in many applications. To improve the throughput of the transactions, zkRollups and zkEVM techniques using the cryptographic primitive of zero-knowledge proofs (ZKPs) have been proposed and many companies are adopting these technologies in the layer-2 solutions. However, in these technologies, the proof generation of the ZKP is the bottleneck and the companies have to deploy powerful machines with TBs of memory to batch a large number of transactions in a ZKP.In this work, we improve the scalability of these techniques by proposing new schemes of fully distributed ZKPs. Our schemes can improve the efficiency and the scalability of ZKPs using multiple machines, while the communication among the machines is minimal. With our schemes, the ZKP generation can be distributed to multiple participants in a model similar to the mining pools. Our protocols are based on Plonk, an efficient zero-knowledge proof system with a universal trusted setup. The first protocol is for data-parallel circuits. For a computation of M sub-circuits of size T each, using M machines, the prover time is O(T log T + M log M), while the prover time of the original Plonk on a single machine is O(MT log(MT )). Our protocol incurs only O(1) communication per machine, and the proof size and verifier time are both O(1), the same as the original Plonk. Moreover, we show that with minor modifications, our second protocol can support general circuits with arbitrary connections while preserving the same proving, verifying, and communication complexity. The technique is general and may be of independent interest for other applications of ZKP.We implement Pianist (Plonk vIA uNlimited dISTribution), a fully distributed ZKP system using our protocols. Pianist can generate the proof for 8192 transactions in 313 seconds on 64 machines. This improves the scalability of the Plonk scheme by 64×. The communication per machine is only 2.1 KB, regardless of the number of machines and the size of the circuit. The proof size is 2.2 KB and the verifier time is 3.5 ms. We further show that Pianist has similar improvements for general circuits. On a randomly generated circuit with 225gates, it only takes 5 s to generate the proof using 32 machines,24.2× faster than Plonk on a single machine.
2 source records
Cryptography and Data Security
Advanced Steganography and Watermarking Techniques
With the rapid development of the Industrial Internet of Things, a vast amount of data generates, collects, and processes, playing a crucial role in industrial production and operations. Addressing issues of privacy leakage, identity forgery, and data security during data transmission in IIoT, this paper proposes a data security transmission and privacy protection scheme based on blockchain technology. The scheme employs zero-knowledge proof algorithms for identity authentication of terminal devices to ensure the privacy of device information is not compromised, effectively preventing identity forgery and attacks. Additionally, it uses attribute-based encryption to secure the data's confidentiality. To ensure efficient data storage and the security of encryption keys, the scheme utilizes IPFS for on-chain querying and off-chain storage of data. The security of the proposed scheme is analyzed theoretically, and its computational overhead is evaluated experimentally. The results show that this scheme has lower computational overhead compared to other schemes, while significantly enhancing security and reliability.
With the continuous advancement of information technology, a growing number of works, including articles, paintings, and music, are being digitized. Digital content can be swiftly shared and disseminated via the Internet. However, it is also vulnerable to malicious plagiarism, which can seriously infringe upon the rights of creators and dampen their enthusiasm. To protect creators’ rights and interests, a sophisticated method is necessary to authenticate digital intellectual property rights. Traditional authentication methods rely on centralized, trustworthy organizations that are susceptible to single points of failure. Additionally, these methods are prone to network attacks that can lead to data loss, tampering, or leakage. Moreover, the circulation of copyright information often lacks transparency and traceability in traditional systems, which leads to information asymmetry and prevents creators from controlling the use and protection of their personal information during the authentication process. Blockchain technology, with its decentralized, tamper-proof, and traceable attributes, addresses these issues perfectly. In blockchain technology, each node is a peer, ensuring the symmetry of information. However, the transparent feature of blockchains can lead to the leakage of user privacy data. Therefore, this study designs and implements an Ethereum blockchain-based intellectual property authentication scheme with privacy protection. Firstly, we propose a method that combines elliptic curve cryptography (ECC) encryption with digital signatures to achieve selective encryption of user personal information. Subsequently, an authentication algorithm based on Zero-Knowledge Succinct Non-Interactive Argument of Knowledge (zk-SNARK) is adopted to complete the authentication of intellectual property ownership while encrypting personal privacy data. Finally, we adopt the InterPlanetary File System (IPFS) to store large files, solving the problem of blockchain storage space limitations.
Open access
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Stephan Rau, Alexander Rau, Johanna Nattenmüller, Anna Maria Fink · 7 authors
BACKGROUND: We investigated the potential of an imaging-aware GPT-4-based chatbot in providing diagnoses based on imaging descriptions of abdominal pathologies. METHODS: Utilizing zero-shot learning via the LlamaIndex framework, GPT-4 was enhanced using the 96 documents from the Radiographics Top 10 Reading List on gastrointestinal imaging, creating a gastrointestinal imaging-aware chatbot (GIA-CB). To assess its diagnostic capability, 50 cases on a variety of abdominal pathologies were created, comprising radiological findings in fluoroscopy, MRI, and CT. We compared the GIA-CB to the generic GPT-4 chatbot (g-CB) in providing the primary and 2 additional differential diagnoses, using interpretations from senior-level radiologists as ground truth. The trustworthiness of the GIA-CB was evaluated by investigating the source documents as provided by the knowledge-retrieval mechanism. Mann-Whitney U test was employed. RESULTS: The GIA-CB demonstrated a high capability to identify the most appropriate differential diagnosis in 39/50 cases (78%), significantly surpassing the g-CB in 27/50 cases (54%) (p = 0.006). Notably, the GIA-CB offered the primary differential in the top 3 differential diagnoses in 45/50 cases (90%) versus g-CB with 37/50 cases (74%) (p = 0.022) and always with appropriate explanations. The median response time was 29.8 s for GIA-CB and 15.7 s for g-CB, and the mean cost per case was $0.15 and $0.02, respectively. CONCLUSIONS: The GIA-CB not only provided an accurate diagnosis for gastrointestinal pathologies, but also direct access to source documents, providing insight into the decision-making process, a step towards trustworthy and explainable AI. Integrating context-specific data into AI models can support evidence-based clinical decision-making. RELEVANCE STATEMENT: A context-aware GPT-4 chatbot demonstrates high accuracy in providing differential diagnoses based on imaging descriptions, surpassing the generic GPT-4. It provided formulated rationale and source excerpts supporting the diagnoses, thus enhancing trustworthy decision-support. KEY POINTS: • Knowledge retrieval enhances differential diagnoses in a gastrointestinal imaging-aware chatbot (GIA-CB). • GIA-CB outperformed the generic counterpart, providing formulated rationale and source excerpts. • GIA-CB has the potential to pave the way for AI-assisted decision support systems.
Open access
Artificial Intelligence in Healthcare and Education
Chenhao Shi, Ruibang Liu, H. B. Chen, Guoqiang Li · 5 authors
The communities of blockchains and distributed ledgers have been stirred up by the introduction of zero-knowledge proofs (ZKPs). Originally designed as a solution to privacy issues, ZKPs have now evolved into an effective remedy for scalability concerns. To enable ZKPs, Rank-1 Constraint Systems (R1CSs) offer a verifier for bilinear equations. In order to accurately and efficiently represent R1CSs, several language tools, such as Circom, Noir, and Snarky, have been proposed to automate the compilation of advanced programs into R1CSs. However, due to the flexible nature of R1CS representation, there can be significant differences in the compiled R1CS forms generated from circuit language programs with the same underlying semantics. To address this issue, this article puts forth a dataflow-based R1CS paradigm algorithm, which produces a standardized format for different R1CS instances with identical semantics. Additionally, we present an R1CS benchmark, and our experimental evaluation demonstrates the efficacy of our methods.
Robert G. Werner, Dominique Briechle, Marit Elke Anke Mathiszig
Currently, the ad hoc, one-way distribution of pharmaceuticals from pharmacies to their customers is inefficient and high in emissions. The HitchhikeBox concept aims to improve the current logistics system by utilizing existing transport channels. This eliminates the need for single-purpose delivery trips and personnel. The system is open to competing service providers, with fully automated contract management, payment and sanctioning of the parties involved. The system utilizes asymmetric encryption and zero-knowledge proofs to guarantee user privacy and non-traceability of deliveries for contracts, payments, and sensor data. The system is designed to be resilient, self-governing and suitable for highly sensitive goods, such as the transport of pharmaceuticals, by ensuring their optimal condition. In addition, the system utilizes smart contracts to conclude and enforce contracts, as well as a distributed off-chain cluster to process and store data in a GDPR-compliant manner. The HitchhikeBox concept facilitates semi-automated, cost-effective and eco-friendly logistics while maintaining reliability, privacy and liability.
This article introduces a new asynchronous Byzantine-tolerant asset transfer system (cryptocurrency) with three noteworthy properties: quasi-anonymity, lightness, and consensus-freedom. Quasi-anonymity means no information is leaked regarding the receivers and amounts of the asset transfers. Lightness means that the underlying cryptographic schemes are \textit{succinct}, and each process only stores data polylogarithmic in the number of its own transfers.Consensus-freedom means the system does not rely on a total order of asset transfers. The proposed algorithm is the first asset transfer system that simultaneously fulfills all these properties in the presence of asynchrony and Byzantine processes. To obtain them, the paper adopts a modular approach combining a new distributed object called agreement proofs and well-known techniques such as vector commitments, universal accumulators, and zero-knowledge proofs. The paper also presents a new non-trivial universal accumulator implementation that does not need knowledge of the underlying accumulated set to generate (non-)membership proofs, which could benefit other crypto-based applications.
The closed architecture of prevailing blockchain systems renders the usage of this technology mostly infeasible for a wide range of real-world problems. Most blockchains trap users and applications in their isolated space without the possibility of cooperating or switching to other blockchains. Therefore, blockchains need additional mechanisms for seamless communication and arbitrary data exchange between each other and external systems. Unfortunately, current approaches for cross-blockchain communication are resource-intensive or require additional blockchains or tailored solutions depending on the applied consensus mechanisms of the connected blockchains. Therefore, we propose an oracle with an off-chain aggregation mechanism based on Zero-Knowledge Succinct Non-interactive Arguments of Knowledge (zk-SNARKs) to facilitate cross-blockchain communication. The oracle queries data from another blockchain and applies a rollup-like mechanism to move state and computation off-chain. The zkOracle contract only expects the transferred data, an updated state root, and proof of the correct execution of the aggregation mechanism. The proposed solution only requires constant 378 kgas to submit data on the Ethereum blockchain and is primarily independent of the underlying technology of the queried blockchains.
In this article, we present a cutting-edge private voting system that prioritizes anonymity, using Zero-knowledge Proof (ZKP) technology. Our solution utilizes a Solidity smart contract to manage secure voting on the blockchain. In our method, voters can anonymously submit their votes after successfully verifying their identities using ZKP. This process unfolds in three stages. Initially, voters authenticate their identities on their machines. Once verified, a proof of the successful authentication is generated. This proof, accompanied by the confidential vote, is then sent for verification by a smart contract verifier embedded in the system. The verifier evaluates the proof and proceeds only if the criteria are met. Votes that pass verification are securely stored. Our innovation represents a significant step forward in blockchain-based private voting, promising enhanced transparency, security, and privacy. By blending cryptographic methods with blockchain technology, we offer a strong and trustworthy approach that safeguards the integrity of each voter's input.
Internet Traffic Analysis and Secure E-voting
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
Alexandr Kuznetsov, Alex Rusnak, Anton Yezhov, Dzianis Kanonik · 6 authors
Zero-knowledge proofs have emerged as a powerful tool for enhancing privacy and security in blockchain applications. However, the efficiency and scalability of proof systems remain a significant challenge, particularly in the context of Merkle tree inclusion proofs. Traditional proof aggregation techniques based on AND logic suffer from a high verification complexity and data communication overhead, limiting their practicality for large-scale applications. In this paper, we propose a novel proof aggregation approach based on OR logic, which enables the generation of compact and universally verifiable proofs for Merkle tree inclusion. By adapting and extending the concept of OR composition from Sigma protocols, we achieve a proof size that is independent of the number of leaves in the tree, and verification can be performed using any single valid leaf hash. This represents a significant improvement over AND aggregation, which requires the verifier to process all leaf hashes. We formally define the OR aggregation logic; describe the process of generating universal proofs; and provide a comparative analysis that demonstrates the advantages of our approach in terms of proof size, verification data, and universality. Furthermore, we discuss the potential of combining OR and AND aggregation logics to create complex acceptance functions, enabling the development of expressive and efficient proof systems for various blockchain applications. The proposed techniques have the potential to significantly enhance the scalability, efficiency, and flexibility of zero-knowledge proof systems, paving the way for more practical and adaptive solutions in large-scale blockchain ecosystems.
Jie Li, Yuanyuan Lin, Yibing Li, Yan Zhuang · 5 authors
The Internet of Vehicles (IoV) connects an isolated individual on the road to share information, which can improve traffic efficiency. However, the promotion of information sharing brings the critical security issues of identity authentication, followed by privacy protection issues in the authentication process in the IoV. In this study, we designed a blockchain-based conditional privacy-preserving authentication scheme for the IoV (BPA). Our scheme implements zero-knowledge proof (ZKP) to verify the identities of vehicles, which moves the authentication process down to the Roadside Units (RSUs) and achieves decentralized authentication at the edge nodes. Moreover, blockchain technology is utilized to synchronize a consistent ledger across all RSUs for recording and disseminating vehicle authentication states, which enhances the overall authentication process efficiency. We provide a theoretical analysis asserting that the BPA ensures enhanced security and effectively protects the privacy of all participating vehicles. Experimental evaluations confirm that our scheme outperforms existing solutions in terms of the computational and communication overhead.