Data sharing is a crucial step in the research community to make the most of the prior effort. Platforms for sharing data currently in use rely on trustworthy third parties (TTP). Such systems lack immutability, security, transparency, and trust because of TTPâs involvement. In order to address these problems, the proposed system approaches an Interplanetary File System (IPFS)-based blockchain-based secure data sharing platform. The user uploads a data file to the IPFS server, which is subsequently split up into several secret shares. By carrying out the access responsibilities that the user has specified in the smart contract, the suggested scheme accomplishes security and access control. This scenario combines encryption, Ethereum blockchain technology, decentralized storage, and incentive systems. Solidity smart contracts are created and deployed on a local Ethereum test network in order to carry out the suggested scenario. Transparency, Security, Access control, Owner authenticity, and Data quality are all achieved by the suggested plan.
The ongoing public interest in blockchains and smart contracts has brought a rise to a magnitude of different blockchain implementations. The rate at which new concepts are envisioned and implemented makes it hard to vet their impact on security. Especially smart contract platforms, executing untrusted code, are very complex by design. Still, people put their trust and money into chains that may lack proper testing. A behavior deviation for edge cases of single op-codes is a critical bug class in this brave new world. It can be abused for Denial of Service against the blockchain, chain splits, double-spending, or direct attacks on applications operating on the blockchain. In this paper, we propose an automated methodology to uncover such differences. Through coverage-guided and state-guided fuzzing, we explore smart contract virtual machine behavior against multiple VMs in parallel. We develop NeoDiff, the first framework for feedback-guided differential fuzzing of smart contract VMs. We discuss real, monetary consequences our tool prevents. NeoDiff can be ported to new smart contract platforms with ease. Apart from fuzzing Ethereum VMs, NeoDiff found a range of critical differentials in VMs for the Neo blockchain. Moreover, through a higher-layer semantics mutator, we uncovered semantic discrepancies between Neo smart contracts written in Python when executed on the blockchain vs. classic CPython. Along the way, NeoDiff uncovered memory corruptions in the C# Neo VM.
Cyprien Delpech de Saint Guilhem, Emmanuela Orsini, Titouan Tanguy
This work introduces a new interactive oracle proof system based on the MPC-in-the-Head paradigm. To improve concrete efficiency and offer flexibility between computation time and communication size, a generic proof construction based on multi-round MPC protocols is proposed, instantiated with a specific protocol and implemented and compared to similar proof systems.
Cryptocurrency nowadays is in most demand and many people are investing in these currencies to get high returns. Its is more frequently used as it is theft proof, accessible anywhere and anytime. By using crypto currency the settlement of money is instant. Many websites and applications provide us information about the rates of different crypto currencies available in the Crypto Market. So we will be building an application in which we will be displaying the real time rates of different crypto currencies inside our application.
Today there is considerable interest in deploying blockchains and\ndecentralized ledger technology as a means to address the deficiencies of\ncurrent financial and digital asset infrastructures. The focal point of\nattention in many projects on digital asset and cryptocurrency is centered\naround blockchain systems and smart contracts. Many projects seek to make the\nblockchain as the centerpiece of the new decentralized world of finance.\nHowever, several roadblocks and challenges currently face this predominant\nblockchain-centric view. In this paper we argue that the proper and correct\nperspective on decentralized economy should be one that is asset-centric, where\nthe goal should be the consistent lifecycle management of assets in the\nreal-world with their digital representation on the blockchain. We introduce\nthe notion of the digital twin to capture the relationship between a real-world\nasset and its on-chain representation. A digital twin container is utilized to\npermit off-chain state persistence and on-chain state traceability, where the\ncontainer can be deployed on the blockchain as well as on traditional\napplication servers. The digital twin container becomes the bridge between\nlegacy infrastructures and the newly emergent blockchain infrastructures,\npermitting legacy systems to interoperate consistently with blockchain systems.\nWe believe this asset-centric view to be the correct evolutionary direction for\nthe nascent field of blockchains and decentralized ledger technology.\n
Haekal Febriansyah Ramadhan, Fandi Aditya Putra, Riri Fitri Sari
News is a form of information sharing that tells the people about current event that is happening. With the advancement of technologies, the rate of spreading of the news is also increasing. One of the most popular places to read news is through the Internet. However, most of the people that read news from the Internet is not aware about the news sources. This leads to the spread of some fake news in society. In this paper, we suggest a way to verify a news using Ethereum smart contract and IPFS. There are four entities that involved in the system, such as Journalist as the one that provides the news, Validator as the one that will rate the news, Ethereum Smart Contract that will store the data inside the blockchain, and IPFS that will store the news and giving hash code to be stored inside the blockchain. This paper also analyzed the cost required to run the function of the smart contract deployed. The result is that all of the Rating Functions cost the same. However, the News Submit Function is not. The difference is the bigger the news stored in the IPFS, the more expensive the cost required to run the function.
Viraaji Mothukuri, Sai S. Cheerla, Reza M. Parizi, Qi Zhang ¡ 5 authors
Hadoop Distributed File System (HDFS) is one of the widely used distributed file systems in big data analysis for frameworks such as Hadoop. HDFS allows one to manage large volumes of data using low-cost commodity hardware. However, vulnerabilities in HDFS can be exploited for nefarious activities. This reinforces the importance of ensuring robust security to facilitate file sharing in Hadoop as well as having a trusted mechanism to check the authenticity of shared files. This is the focus of this paper, where we aim to improve the security of HDFS using a blockchain-enabled approach (hereafter referred to as BlockHDFS). Specifically, the proposed BlockHDFS uses the enterprise-level Hyperledger Fabric platform to capitalize on files' metadata for building trusted data security and traceability in HDFS.
Isaac Adjei-Mensah, Isaac Osei Agyemang, Collins Sey, Linda Delali Fiasam ¡ 5 authors
From online education and trading, all aspects of our lives are affected by digital technology. Among them, the storage of music has also entered the digital era. Music productions created by artists have brought great joy to people. However, when artists upload their works, they are most downloaded and reprinted by others, and copyright information and the issue associated with the sharing of music arise. This will have a significant negative impact on the enthusiasm and motivation of artists. This paper provides an internet database platform for artists, which uses the distributed and tamper-proof technology of the Ethereum blockchain to store music works, and protect the copyright information of each album or music produced by artists in the music industry. Design and implementation of the system model and data storage are proposed and data storage processes based on the Ethereum smart contract are demonstrated in detail. The system stores music information on the blockchain network, using the smart contract to provide artists with a fast and efficient royalty payment. Node.js is applied to carry out the experiments of our system, and we test Remote Procedure Calls (RPC) with available account and private keys for contract development and use block explorer to track music information on the blockchain. Our system enables copyright revenue to be attributed to music creators that will help to eliminate the illegal uploading of music on other websites.
This paper concentrates on the hardware implementation of efficient and re- configurable elliptic curve digital signature algorithm (ECDSA) that is suitable for verifying transactions in Blockchain related applications. Despite ECDSA architecture being computationally expensive, the usage of a dedicated stand-alone circuit enables speedy execution of arithmetic operations. The prototype put forth supports N-bit elliptic curve cryptography (ECC) group operations, signature generation and verification over a prime field for any elliptic curve. The research proposes new hardware framework for modular multiplication and modular multiplicative inverse which is adopted for group operations involved in ECDSA. Every hardware design offered are simulated using modelsim register transfer logic (RTL) simulator. Field programmable gate array (FPGA) implementation of var- ious modules within ECDSA circuit is compared with equivalent existing techniques that is both hardware and software based to highlight the superiority of the suggested work. The results showcased prove that the designs implemented are both area and speed efficient with faster execution and less resource utilization while maintaining the same level of security. The suggested ECDSA structure could replace the software equivalent of digital signatures in hardware blockchain to thwart software attacks and to provide better data protection.
Ethereum as one of the largest blockchain systems plays an important role in the distributed ledger, database systems, etc. As more and more blocks are mined, the storage burden of Ethereum is significantly increased. The current Ethereum system uniformly transforms all its data into key-value (KV) items and stores them to the underlying Log-Structure Merged tree (LSM-tree) storage engine ignoring the software semantics. Consequently, it not only exacerbates the write amplification effect of the storage engine but also hurts the performance of Ethereum. In this paper, we proposed a new Ethereum-aware storage model called Block-LSM, which significantly improves the data synchronization of the Ethereum system. Specifically, we first design a shared prefix scheme to transform Ethereum data into ordered KV pairs to alleviate the key range overlaps of different levels in the underlying LSM-tree based storage engine. Moreover, we propose to maintain several semantic-orientated memory buffers to isolate different kinds of Ethereum data. To save space overhead, Block-LSM further aggregates multiple blocks into a group and assigns the same prefix to all KV items from the same block group. Finally, we implement Block-LSM in the real Ethereum environment and conduct a series of experiments. The evaluation results show that Block-LSM significantly reduces up to 3.7Ă storage write amplification and increases throughput by 3Ă compared with the original Ethereum design.
We present FAWAC, a distributed ledger architecture and consensus strategy that is decentralized, attack-resistant and provides real-world impact through completion of useful work. A multi-enclave architecture separates fast transaction consensus from computational hard tasks used for validator selection. FAWAC uses an Inter-Planetary File System (IPFS) back-end to provide seamless connection between the enclaves and a modified Byzantine Agreement consensus, which actively checks for faulty behavior, to secure the network. This work provides an architectural level overview of the proposed system design.
MohammadAmin Fazli, Ali Owfi, Mohammad Reza Taesiri
Non Fungible Tokens (NFTs) have gained a solid foothold within the crypto community, and substantial amounts of money have been allocated to their trades. In this paper, we studied one of the most prominent marketplaces dedicated to NFT auctions and trades, Foundation. We analyzed the activities on Foundation and identified several intriguing underlying dynamics that occur on this platform. Moreover, We performed social network analysis on a graph that we had created based on transferred NFTs on Foundation, and then described the characteristics of this graph. Lastly, We built a neural network-based similarity model for retrieving and clustering similar NFTs. We also showed that for most NFTs, their performances in auctions were comparable with the auction performance of other NFTs in their cluster.
The central bank digital currency (CBDC) is gaining popularity for the last few years in many countries as it will affect the entire ecosystem of the current financial infrastructure. The CBDC utilizes digital tokens to indicate any nation's fiat/stable currency that manages under distributed ledger technology such as blockchain. Compared to existing cryptocurrencies, the CBDC is regulated by the government monetary policies, including the issuance of digital tokens (i.e., digitized central bank money) and circulation of these digital tokens to the commercial banks, then to the public/end-users. This paper proposes a two-layered CBDC architecture after analyzing the recent research and existing CBDC pilot projects. The distribution layer shows wholesale CBDC based on permission blockchain network (PBN) between the central bank and the commercial banks. While, the user layer describes the functioning of retail CBDC, which shows the interaction between the commercial banks and the end-users through the token-based account. We aim to provide the CBDC design architecture and smart-contract functions for PBN.
Andreas Zeiselmair, Bernd Steinkopf, Ulrich GallersdÜrfer, Alexander Bogensperger ¡ 5 authors
The energy system is becoming increasingly decentralized. This development requires integrating and coordinating a rising number of actors and small units in a complex system. Blockchain could provide a base infrastructure for new tools and platforms that address these tasks in various aspectsâranging from dispatch optimization or dynamic load adaption to (local) market mechanisms. Many of these applications are currently in development and subject to research projects. In decentralized energy markets especially, the optimized allocation of energy products demands complex computation. Combining these with distributed ledger technologies leads to bottlenecks and challenges regarding privacy requirements and performance due to limited storage and computational resources. Verifiable computation techniques promise a solution to these issues. This paper presents an overview of verifiable computation technologies, including trusted oracles, zkSNARKs, and multi-party computation. We further analyze their application in blockchain environments with a focus on energy-related applications. Applied to a distinct optimization problem of renewable energy certificates, we have evaluated these solution approaches and finally demonstrate an implementation of a Simplex-Optimization using zkSNARKs as a case study. We conclude with an assessment of the applicability of the described verifiable computation techniques and address limitations for large-scale deployment, followed by an outlook on current development trends.
Christos Chrysoulas, A. M. Thomson, Nikolaos Pitropakis, Pavlos Papadopoulos ¡ 10 authors
The continuously advancing digitization has provided answers to the bureaucratic problems faced by eGovernance services. This innovation led them to an era of automation it has broadened the attack surface and made them a popular target for cyber attacks. eGovernance services utilize internet, which is currently a location addressed system where whoever controls the location controls not only the content itself, but the integrity of that content, and the access to that content. We propose GLASS, a decentralised solution which combines the InterPlanetary File System (IPFS) with Distributed Ledger technology and Smart Contracts to secure EGovernance services. We also create a testbed environment where we measure the IPFS performance.
Phillipe Austria, Chol Hyun Park, Alex Hoffman, Yoohwan Kim
Cloud storage has become a prevalent choice for data storage for both business and personal use due to increasing data use. While cloud storage services, such as Google Drive, provide customers with high levels of data integrity and security, customers however lose privacy and require trust in the service provider to not act maliciously with their data. We explore an alternative to centralized, traditional cloud storage (TCS) using blockchain technology. In this paper, we tested and evaluated the performance and cost of Sia, a decentralized blockchain-based storage platform (BBS) that ensures users' privacy. The platform allows users to rent storage space from other users in exchange for Siacoin, Sia's native currency. Metrics were evaluated through various storage tests and results were compared to Google Drive. Performance tests showed Sia's available time, how long it takes for a file to upload and be download ready, to be 8â12 times slower than Google Drive. In contrast, Sia downloads were 2â3 times faster. Cost test revealed Sia's overall storage spending to be comparable to Google Drive and other popular TCS; however, results raised questions about spending details. Further testing is needed to fully understand the complexities of a BBS platform like Sia.
Jongyeop Kim, Hayden Wimmer, Hong Liu, Seong-Soo Kim
Big data analysis for accurate predictions requires adherence to systematic procedures. This study shows an entire data analysis phase from the data collection to model evaluation using the Long Short-Term memory(LSTM) for cryptocurrency price prediction. Three different coin prices are directly collected from the CoinMarketCap in nearly real-time by applying the web scraping technique. The LSTM model trained with this data varying random seed or static seed parameters to find optimal conditions, leading to better accuracy of the LSTM model. Our model evaluated their accuracy in terms of MAE, RMSE, and SMAPE indicators. As a result of this experiment, most of the best candidate parameters are classified at the fixed seed trail in terms of the RMSE for Bit coin, Ethereum, and Lite Coin.
Smart contracts, scripts at the heart of blockchain-based applications, are meant to be available forever once deployed. However, this property has a price. The amount of space required to store new contracts keeps increasing. This increase impacts each participating node's performance and makes it inconvenient for low-end devices to participate in the network. Among all contracts deployed in the blockchain, a vast majority will lead to little if any usage. We demonstrate that, in the course of one year, 70 % of deployed contracts lead to no use. Unfortunately, unused contracts keep occupying space on the blockchain. To tackle this issue, we propose a new protocol to identify and delete unused contracts. Through simulation, based on Ethereum historical data, we show that deletion of smart contracts after an inactivity period of 90 days could lead to a 66 % reduction in the number of contracts stored over a year.
Ethereum platform operates with rich spectrum of data structures and hashing and coding functions. The main source describing them is the Yellow paper, complemented by a lot of informal blogs. These sources are somehow limited. In particular, the Yellow paper does not ideally balance brevity and detail, in some parts it is very detail, while too shallow elsewhere. The blogs on the other hand are often too vague and in certain cases contain incorrect information. As a solution, we provide this document, which summarises data structures used in Ethereum. The goal is to provide sufficient detail while keeping brevity. Sufficiently detailed formal view is enriched with examples to extend on clarity.
Abstract Existing models for non-interactive MPC cannot provide full privacy for inputs, because they inherently leak the residual function (i.e., the output of the function on the honest partiesâ input together with all possible values of the adversarial inputs). For example, in any non-interactive sealed-bid auction, the last bidder can figure out what was the highest previous bid. We present a new MPC model which avoids this privacy leak. To achieve this, we utilize a blockchain in a novel way, incorporating smart contracts and arbitrary parties that can be incentivized to perform computation (âbounty hunters,â akin to miners). Security is maintained under a monetary assumption about the parties: an honest party can temporarily supply a recoverable collateral of value higher than the computational cost an adversary can expend. We thus construct non-interactive MPC protocols with strong security guarantees (full security, no residual leakage) in the short term. Over time, as the adversary can invest more and more computational resources, the security guarantee decays. Thus, our model, which we call Gage MPC, is suitable for secure computation with limited-time secrecy, such as auctions. A key ingredient in our protocols is a primitive we call âGage Time Capsulesâ (GaTC): a time capsule that allows a party to commit to a value that others are able to reveal but only at a designated computational cost. A GaTC allows a party to commit to a value together with a monetary collateral. If the original party properly opens the GaTC, it can recover the collateral. Otherwise, the collateral is used to incentivize bounty hunters to open the GaTC. This primitive is used to ensure completion of Gage MPC protocols on the desired inputs. As a requisite tool (of independent interest), we present a generalization of garbled circuit that are more robust: they can tolerate exposure of extra input labels. This is in contrast to Yaoâs garbled circuits, whose secrecy breaks down if even a single extra label is exposed. Finally, we present a proof-of-concept implementation of a special case of our construction, yielding an auction functionality over an Ethereum-like blockchain.
Archives, both analogue and digital, are primarily concerned with preserving records as originals. Because of this, immutable data as used in a blockchain data structure seem a logical choice when designing such systems. At the same time, archives maintain records which may need to change over the long term. It is a requirement of archival preservation to be able to update recordsâ metadata in order not only to guarantee authenticity after digital preservation actions but also to ensure that relationships to other records, which might be created after an original record has entered the archive (and has been registered in a blockchain), can be maintained. The need to maintain an archival bond, which represents a network of relationships between aggregation of records, i.e., the relationship connecting previous and subsequent records belonging to the same activity, is a prime example of this requirement. This paper explores realisation of the archival bond in the context of blockchain-based archival system by proposing a supporting database system which enables metadata to be changed as required but also significantly simplifies searching compared to searching on-chain information, while keeping the immutability characteristic of blockchain.
We define a technique for analyzing updates of smart contracts balances due to transfers of digital assets. The analysis addresses a lightweight smart contract language and consists of a two-step translation. First, we define the input-output behaviors of smart contract functions by means of a simple functional language with static dispatch. Then we associate the terms of this intermediate language with cost equations that compute the loss or gain of digital assets. The resulting equations can be fed to an off-the-shelf cost analyzer to provide upper bounds to the loss or gain. Our analysis has been prototyped and we report its assessments and discuss extensions with additional features.