Ring confidential transactions (RingCT) is a classical protocol that enhances transaction privacy within blockchain technology. It is primarily utilized in anonymous cryptocurrencies such as Monero. In recent years, to counter the security threats posed by quantum computing to classical RingCT (C-RCT), several post-quantum RingCT (P-RCT) protocols were proposed. However, prior studies do not address the account transition from C-RCT to P-RCT, which is essential to ensure the quantum resistance and usability of user accounts following the upgrade from C-RCT to P-RCT. In this article, we introduce a RingCT account transition protocol (RAT), which allows users to migrate their accounts from the blockchain with C-RCT to that with P-RCT. The protocol consists of two cryptographic components: 1) a zero-knowledge proof scheme used to prove that two group generators correspond to the same witness and 2) a cross-cryptosystems commitment transition protocol. RAT is fully decentralized and does not require any trusted third parties. Additionally, the transition process does not disclose the account balance and maintains both atomicity and consistency. The security of our protocol relies on the cryptographic components within RingCT, without the need for additional security assumptions, such as a trusted setup. The experimental results demonstrate the effectiveness of our protocol in practice.
Abstract The adoption of digital assets and distributed ledger technology in finance is rapidly increasing. This adoption introduces new types of risks, currently not adequately covered in conventional risk management frameworks. This paper identifies, reviews, and categorises these risks. It draws on a systematic review of literature and classifies the vulnerabilities by layer—network layer, consensus layer, protocol layer, and enablement layer.
Ethereum enables the creation and execution of decentralized applications through smart contracts, that are compiled to Ethereum Virtual Machine (EVM) bytecode. Once deployed in the blockchain, the bytecode is immutable; hence, ensuring that smart contracts are bug-free before their deployment is of utmost importance. A crucial preliminary step for any effective static analysis of EVM bytecode is the extraction of the control-flow graph (CFG): this presents significant challenges due to potentially statically unknown jump destinations. In this paper we present a novel approach, based on abstract interpretation, aiming at building a sound CFG from EVM bytecode smart contracts. Our analysis, which is implemented in our static analyzer EVMLiSA, is based on a parametric abstract domain that approximates concrete execution stacks at each program point as an l-sized set of abstract stacks of maximal height h; the results of the analysis are then used to resolve the jump destinations at jump nodes. In our preliminary experiments, by fine-tuning the analysis parameters, EVMLiSA builds sound CFGs for all smart contracts where permanent storage-related opcodes do not influence jump destinations.
William Fernando Martínez Luna, Ana María Moreno Ballesteros, Edgar José Ruiz Dorantes
NFTs (non-fungible tokens) enable the commercialization of goods and services through blockchain technology, enhancing the security, transparency, and speed of transactions. The primary challenge NFTs face is their connection to the underlying asset, ensuring that transferring the token also means transferring the linked asset. This interdisciplinary article examines the technical and legal challenges of creating and linking a digital asset to an NFT. To explain the binding process, an NFT associated with a digital artwork was created, and relevant internal and uniform legal regulations were analyzed.
Juseong Jeon, Sejin Park, Deokwoo Lee, Juncheol Ahn
The blockchain market has been experiencing rapid growth recently. Alongside this, Web3 services based on blockchain technology are expanding and gaining attention. These services can support not only encompass gaming and financial services but also leverage the numerous nodes existing in the network to distribute tasks, thereby supporting parallel computing. However, there is no way to directly access web3 services in the current network topology, which limits the expansion of services. Therefore, the current Web3 relies on centralized web servers as access points for services, resulting in the inevitable loss of benefits associated with decentralization, such as the shift in data sovereignty.
In this study, a new data-sharing method is proposed that uses a private InterPlanetary File System—a decentralized storage system operated within a closed network—to distribute data to external entities while making its authenticity verifiable. Among the two operational modes of IPFS, public and private, this study focuses on the method for using private IPFS. Private IPFS is not open to the general public; although it poses a risk of data tampering when distributing data to external parties, the proposed method ensures the authenticity of the received data. In particular, this method applies a type of zero-knowledge proof, namely, the Groth16 protocol of zk-SNARKs, to ensure that the data corresponds to the content identifier in a private IPFS. Moreover, the recipient’s name is embedded into the distributed data to prevent unauthorized secondary distribution. Experiments confirmed the effectiveness of the proposed method for an image data size of up to 120 × 120 pixels. In future studies, the proposed method will be applied to larger and more diverse data types.
Implementing provable fairness in the minting process of non-fungible tokens (NFTs) enables the procedural generation of NFT metadata that can be verified in a decentralized manner, even when stored off-chain. Until now, smart contracts have required additional on-chain data, such as integrity digests, to support the verification of off-chain NFT metadata. Due to the high costs of on-chain data storage, most NFTs do not implement such validation methods, reducing trust in the NFT's off-chain metadata and increasing reliance on centralization. We propose a new method, inspired by the virtual ecology design of sandbox massively multiplayer online role-playing games (MMORPGs). This method utilizes a 256-bit unsigned integer representing a seed value, a Web3-compatible implementation of a pseudorandom number generator (W3PRNG), and an executable ruleset containing attribute definitions and their probability spaces to procedurally generate NFTs. This methodology provides users with a provably fair way of generating NFTs in an open-ended minting smart contract by imitating Proof-of-Work mining, including an arbitrary amount of work to be performed while initializing the PRNG. Due to the extremely large state space of 2^256 possible seeds, any implementation makes the NFT's economy inherently inflationary, offering more attractive features and higher utility in Web3 and Metaverse design than existing fixed supply NFT collections. Furthermore, such a system implicitly guarantees the veracity of off-chain metadata based on the on-chain seed value and the smart contract's immutable integrity configuration. (First published to the Future of Gaming Discord community in November, 2022)
Blockchain interoperability has become an essential functionality, which enables asset/data transfers across different blockchains. Sidechains have been deemed as a key technique to provide interoperability. However, sidechains are rarely used in practice, this is because sidechain technologies are impractical and non cost-efficient. To make sidechains practical, in this paper, we design a universal sidechain construction named USSC, which applies to a variety of blockchains without forking them. USSC also enables interoperability across heterogeneous blockchains regardless of underlying consensus. This is facilitated by three components: i) a committee selection method, ii) a cross-chain certificate, and iii) a cross-chain bridge based on smart contracts. The proposed committee-selection method guarantees an honest majority within a committee. Through a concrete implementation of USSC, we outline how the proof-of-stake (PoS) and the proof-of-work (PoW) blockchains enable asset transfers. Furthermore, our USSC is more storage-efficient because it produces a smaller size of certificate and only needs partial nodes instead of all sidechain nodes following a blockchain. Thus, USSC can reduce the overhead of storage and communication of nodes. In addition, we prove that USSC achieves a secure sidechain construction with desirable security properties. Finally, we develop a proof-of-concept implementation of USSC using Cardano and Ethereum. Experimental results demonstrate that USSC outperforms PoW and PoS sidechains, in terms of the certificate size.
Alexandr Kuznetsov, Emanuele Frontoni, Alexandr Kuznetsov, Ruslan Shevchuk · 5 authors
In the rapidly evolving field of digital asset management, centralized and decentralized global registries have become essential tools for organizing, tracking, and distributing digital assets. However, existing systems often face challenges regarding security, censorship resistance, interoperability, customizability, and scalability. This research paper aims to address these gaps by proposing a novel decentralized global registry system based on blockchain technology and non-fungible tokens (NFTs). The research paper makes several key contributions to the field of digital asset management. First, it provides a detailed system design for the proposed decentralized global registry, outlining its architectural components, functional modules, and integration with blockchain and NFT technologies. Second, it offers a thorough comparative analysis of the advantages and limitations of the proposed system in relation to existing centralized and decentralized registries. Finally, the paper presents potential use cases and practical applications of the proposed system in various industries, demonstrating its versatility and adaptability to different contexts and requirements. In conclusion, this research paper contributes significantly to the ongoing efforts to improve digital asset management by presenting a novel, decentralized global registry system based on blockchain technology and NFTs. The proposed system addresses the key limitations of existing solutions and offers a promising direction for future research and development in this critical field.
In addressing the significant challenges caused by the expansion of data storage needs in blockchain systems, this paper explores the integration of the InterPlanetary File System (IPFS) with Substrate-based blockchain. By leveraging IPFS for off-chain storage and Substrate for on-chain operations, this system addresses the key challenges such as bloated storage, inefficiency, and accessibility while preserving data distribution and privacy. Through a comparative analysis with an Ethereum-based system, this study reveals significant advantages of the Substrate-IPFS solution. There is a significant reduction in data storage size and faster block confirmation times, leading to potentially lower transaction costs. The proposed approach enhances data privacy through the use of the Blake2 hashing algorithm. Overall, this research showcases the potential of Substrate-IPFS integration in overcoming the limitations of traditional blockchain storage approaches. Further exploration into the storage cost optimisation within the Substrate framework and additional functionalities using modular pallets could pave the way for significant advancements in the distributed data storage.
Recently data assets and digital assets have received significantcant attention. Currently, data assets focus on the data aspects, but digital assets emphasize the asset aspects, thus they have different sets of technology with respect to protocols and infrastructure. This paper proposes to treat data assets as digital assets, and use new Internet protocols and infrastructure initially designed for digital assets for data assets. In this way, the tough problems of data assets can be addressed, and data assets and other digital assets can be treated in an uniform manner on the Web. By doing so, a new architecture is proposed for the next-generation Web (Web3), the new architecture DACS (Data, Applications, Computing Power, Segmentation) has many new features different from traditional Web2 features.
Enhancing privacy on smart contract-enabled blockchains has garnered much attention in recent research. Zero-knowledge proofs (ZKPs) is one of the most popular approaches, however, they fail to provide full expressiveness and fine-grained privacy. To illustrate this, we underscore an underexplored type of Miner Extractable Value (MEV), called Residual Bids Extractable Value (RBEV). Residual bids highlight the vulnerability where unfulfilled bids inadvertently reveal traders' unmet demands and prospective trading strategies, thus exposing them to exploitation. ZKP-based approaches failed to address RBEV as they cannot provide post-execution privacy without some level of information disclosure. Other MEV mitigations like fair-ordering protocols also failed to address RBEV. We introduce Ratel, an innovative framework bridging a multi-party computation (MPC) prototyping framework (MP-SPDZ) and a smart contract language (Solidity), harmonizing the privacy with full expressiveness of MPC with Solidity 's on-chain programmability. This synergy empowers developers to effortlessly craft privacy-preserving decentralized applications (DApps). We demonstrate Ratel's efficacy through two distinguished decentralized finance (DeFi) applications: a decentralized exchange and a collateral auction, effectively mitigating the potential RBEV issue. Furthermore, Ratel is equipped with a lightweight crash-reset mechanism, enabling the seamless recovery of transiently benign faulty nodes. To prevent the crash-reset mechanism abused by malicious entities and ward off DoS attacks, we incorporate a cost-utility analysis anchored in the Bayesian approach. Our performance evaluation of the applications developed under the Ratel framework underscores their competency in managing real-world peak-time workloads.
Bit-decomposition-based zero-knowledge range proofs in the discrete logarithm (DLOG) setting with a transparent setup, e.g., Bulletproof (IEEE S&P 18), Flashproof (ASIACRYPT 22), and SwiftRange (IEEE S&P 24), have garnered widespread popularity across various privacy-enhancing applications. These proofs aim to prove that a committed value falls within the non-negative range [0, 2^N-1] without revealing it, where N represents the bit length of the range. Despite their prevalence, the current implementations still suffer from suboptimal performance. Some exhibit reduced communication costs at the expense of increased computational costs while others experience the opposite. Presently, users are compelled to utilize these proofs in scenarios demanding stringent requirements for both communication and computation efficiency. In this paper, we introduce, FlashSwift, a stronger DLOG-based logarithmic-sized alternative. It stands out for its greater shortness and significantly enhanced computational efficiency compared with the cutting-edge logarithmic-sized ones for the most common ranges where N is no more than 64. It is developed by integrating the techniques from Flashproof and SwiftRange without using a trusted setup. The substantial efficiency gains stem from our dedicated efforts in overcoming the inherent incompatibility barrier between the two techniques. Specifically, when N=64, our proof achieves the same size as Bulletproof and exhibits 1.1 times communication efficiency of SwiftRange. More importantly, compared with the two, it achieves 2.3 times and 1.65 times proving efficiency, and 3.2 times and 1.7 times verification efficiency, respectively. At the time of writing, our proof also creates two new records of the smallest proof sizes, 289 bytes and 417 bytes, for 8-bit and 16-bit ranges among all the bit-decomposition-based ones without requiring trusted setups. Moreover, to the best of our knowledge, it is the first configurable range proof that is adaptable to various scenarios with different specifications, where the configurability allows to trade off communication efficiency for computational efficiency. In addition, we offer a bonus feature: FlashSwift supports the aggregation of multiple single proofs for efficiency improvement. Finally, we provide comprehensive performance benchmarks against the state-of-the-art ones to demonstrate its practicality.
In the ever-expanding landscape of cloud computing, concerns over the privacy of sensitive data have become paramount. This chapter delves into the intricate realm of privacy-preserving data storage and processing in the cloud. It addresses the challenges posed by data ownership, control, and the ever-looming threat of data breaches in cloud environments. Focusing on innovative techniques, the chapter explores encryption mechanisms, secure multi-party computation, and trusted execution environments for privacy-preserving data storage. Additionally, it delves into cutting-edge methods such as privacy-preserving machine learning, secure query processing, and tokenization for safeguarding privacy during data processing in the cloud. Real-world case studies exemplify successful implementations, providing insights into practical applications. The chapter concludes by envisioning future trends, including the integration of blockchain and zero-knowledge proofs, and highlights the challenges and opportunities that lie ahead in the pursuit of privacy preservation in cloud computing.
Ethereum is the first and largest blockchain that supports smart contracts. To enhance scalability and security, one major planned change of Ethereum 2.0 (Eth2) is to upgrade the smart contract interpreter from Ethereum Virtual Machine (EVM) to WebAssembly (WASM). In the meanwhile, many other popular blockchains have adopted WASM. Since Ethereum hosts millions of smart contracts, it is highly desirable to automatically migrate EVM smart contracts to WASM code to foster the prosperity of the blockchain ecosystem, while inheriting the historical transactions from Ethereum. Unfortunately, it is non-trivial to achieve this purpose due to the challenges in converting the EVM bytecode of smart contracts to WASM bytecode and adapting the generated WASM bytecode to the underlying blockchain environment. In particular, none of the existing tools are adequate for this task because they fail to achieve accurate translation and compatibility with the blockchain environment. In this paper, we propose a novel solution and use Eth2 as the target blockchain to demonstrate its feasibility and performance because Eth2 is highly attractive to both industry and academia. Specifically, we develop EVMBT, a novel EVM2WASM bytecode translation framework that not only ensures the fidelity of translation but also supports plugins to improve smart contracts. Extensive experiments demonstrate that EVMBT can successfully translate real-world smart contracts with high fidelity and low gas overhead.
Warmayana I Gede Agus Krisna, Koki Hayashida, Hiroki Minegoshi, Nobuto Oka
To effectively utilize globally distributed materials data, we developed a prototype decentralized materials data management system. The secure, transparent, and efficient management of materials data was achieved using blockchain technology, smart contracts, non-fungible tokens (NFT), and interplanetary file system (IPFS) in Web3. The effectiveness of the prototype was also discussed in the case studies using performance data on materials used in environmental purification and rechargeable batteries.
S Mohammed Ishaq, Arpitha K M, Himanshu Choubey, Mohammed Azeemulla · 5 authors
In an increasingly computerized universe, the secure administration & trading of crypto files and documents has become a critical concern. In this estimate seeks to label this issue beside creating decentralized implementation (App) that uses distributed larger technology and deep neural network models to enable secure and efficient digital asset management, with an emphasis on NFTs. The App's features include secure wallet network, NFT picture production, stamp out, a sale out, and account handling. The App's backend is built on the Goerli development network with reliability intelligent contracts, while IPFS and ReactJS/Ethers are utilized for scattered storage and client development, individually. Furthermore, the Open AI Api is used to create unique NFT picture depends on customer input. This design showcases the actual application of distributed larger technology and deep neural network models for creating Apps for assured and scattered crypto asset management. Universal, the project adds to the continuing study on blockchain-based solutions for secure digital asset management, while also emphasizing the power of distributed larger technology and deep neural network models to change the way we handle and trade crypto assets.
Abstract The evolution of decentralized storage, propelled by blockchain advancements, has revolutionized data management. This paper focuses on content security in the InterPlanetary File System (IPFS), a leading decentralized storage network lacking inherent content encryption. To address this vulnerability, we propose a novel hybrid cryptographic algorithm, merging AES 128-bit encryption with Elliptic Curve Cryptography (ECC) key generation. The algorithm includes ECC key pairs, random IV generation, and content/AES key encryption using ECC public keys. Benchmarking against standard AES 256-bit methods shows a significant 20% acceleration in encryption speed and a 16% increase in decryption efficiency, affirming practicality for enhancing IPFS content security. This research contributes to securing decentralized storage and provides a performance-driven solution. The promising results highlight the viability of the proposed approach, advancing understanding and mitigating security concerns in IPFS and similar systems.
Information-centric networking (ICN) has received a wide attention as a next-generation network. Unlike conventional IP networks, which forward packets based on IP addresses, ICNs packets are sent based on the name of the contents which are cached to the routers involved, then delivered to the consumer. Since any participating party can upload content to the ICN, the risk of content poisoning attack (CPA) is ever-present. In CPA, an attacker degrades the cache efficiency by uploading fake content under a real name posting as a legitimate publisher. As a countermeasure to CPA, many existing methods determine the legitimacy of content using digital signatures with public keys, and alerts routers of unjustified content upon detection. However, it is difficult for them to detect fake-CPA attacks which use public keys of fabricated content to generate digital signatures. Most methods also lack counter-measures to spoofed fake-CPA attacks, in which the certification authority (CA) that manages the public key or its staff member colludes with the attacker to rewrite the legitimate publisher’s public key to the attacker’s and inject fake contents that pretends to be authentic contents that are high in popularity into the cache. In this paper, we propose a method to prevent the spoofed fake-CPA by managing content names with IOTA, a distributed ledger technology that blocks tampering of contents registered on the system. We also numerically compare the search time and memory requirement of four search methods that search content names managed in the ledger in the proposed method. As a result, we confirm the trade-off between the search time and memory requirement.
With the evolution of Web3.0 and decentralized applications (Dapps), increasing business logic is running on the blockchain. Blockchain storage, as the core infrastructure supporting the increasing volume of data, plays a crucial role. However, the performance and cost of blockchain storages are suffering seriously, which inspires us to re-examine the design of blockchain storage based on the blockchain data characteristics. We propose LETUS, a Log-structured Efficient Trusted Universal Storage for blockchain, providing cryptographic tamper evidence with excellent performance and resource efficiency. (1) LETUS breaks the traditional two-layered architecture and pushes down the Authenticated Data Structure (ADS) into the storage engine to enable fine-grained I/O optimizations. (2) LETUS proposes DMM-Tree which is a novel ADS combining the functionalities of Merkle tree and delta-encoding, significantly reducing storage consumption. (3) LETUS adopts a version-based indexing schema and manages the large volume of pages generated by ADS in a page store indexed by a B-tree variant. (4) LETUS provides a universal solution for different blockchains, such as public blockchains like Ethereum, BNB Smart Chain and AntChain as a representation of consortium blockchains. LETUS has been deployed in AntChain commercial applications, such as NFT and digital torch ignition for 2023 Asian Games. Experimental results also show that with LETUS, AntChain can achieve up to 15.8× improvement in throughput and 80.3% storage cost saving, Ethereum can achieve up to 10.1× improvement in throughput and 75.0% storage cost saving.
Distributed ledger technology such as blockchain is considered essential for supporting large numbers of micro-transactions in the Machine Economy, which is envisioned to involve billions of connected heterogeneous and decentralized cyber-physical systems. This stresses the need for performance and scalability of distributed ledger technologies. Addressing this, sharding techniques that divide the blockchain network into multiple committees are a common approach to improve scalability. However, with current sharding approaches, costly cross-shard verification is needed to prevent double-spending. This article proposes a novel and more scalable distributed ledger method named ScaleGraph that implements dynamic sharding by using routing and logical proximity concepts from distributed hash tables. ScaleGraph addresses cybersecurity in terms of integrity and availability to support frequent micro-transactions between autonomous devices. Benefits of ScaleGraph include a total storage space complexity of \(O(t)\) , where \( t \) is the global number of transactions (assuming a constant replication degree). This space is sharded over \( N \) nodes so that each node needs \(O(t/N)\) storage in expectation, which provides a high level of concurrency and data localization as compared to other delegated consensus proposals. ScaleGraph allows for a dynamic grouping of validators that are selected based on a distance metric. We analyze the consensus requirements in such a dynamic setting and show that a synchronous consensus protocol allows shards to be smaller than an asynchronous one, and likely yields better performance. Moreover, we provide an experimental analysis of security aspects regarding the required size of the consensus groups with ScaleGraph. Our analysis shows that dynamic sharding based on proximity concepts brings attractive scalability properties in general, especially when the fraction of corrupt nodes is small.
The InterPlanetary File System (IPFS) has recently gained considerable attention. While prior research has focused on understanding its performance characterization and application support, it remains unclear: (1) what kind of files/content are stored in IPFS, (2) who are providing these files, (3) are these files always accessible, and (4) what affects the file access performance. To answer these questions, in this paper, we perform measurement and analysis on over 4 million files associated with CIDs (content IDs) that appeared in publicly available IPFS datasets. Our results reveal the following key findings: (1) Mixed file accessibility: while IPFS is not designed for a permanent storage, accessing a non-trivial portion of files, such as those of NFTs and video streams, often requires multiple retrieval attempts, potentially blocking NFT transactions and negatively affecting the user experience. (2) Dominance of NFT (non-fungible token) and video files: about 50% of stored files are NFT-related, followed by a large portion of video files, among which about half are pirated movies and adult content. (3) Centralization of content providers: a small number of peers (top-50), mostly cloud nodes hosted by tech companies, serve a large portion (95%) of files, deviating from IPFS's intended design goal. (4) High variation of downloading throughput and lookup time: large file retrievals experience lower average throughput due to more overhead for resolving file chunk CIDs, and looking up files hosted by non-cloud nodes takes longer. We hope that our findings can offer valuable insights for (1) IPFS application developers to take into consideration these characteristics when building applications on top of IPFS, and (2) IPFS system developers to improve IPFS and similar systems to be developed for Web3.