Liaqat Ali, M. Imran Azim, Jan Peters, Nabin B. Ojha · 10 authors
In this paper, a framework is proposed for integration of peer-to-peer (P2P) trading-based local energy market (LEM) with the blockchain technology. The proposed LEM model allows prosumers and consumers to trade electricity among each other ensuring the presence of the retailer and network utility – who are also essential parts of a P2P network. The P2P contracts settled between various prosumers and consumers are governed by mutually agreed upon smart contracts – which are then written in an Ethereum blockchain to record and store bidding history, P2P transactions, and settlements. An effective formulation is also presented to capture P2P trading quantities and prices among participating prosumers and consumers in a decentralised fashion with an appropriate analysis of financial viability. Finally, a case study is conducted in a real Australian context; in which the engagement of both prosumers and consumers are taken into account, and the performance of the proposed blockchain-enabled LEM is compared with business-as-usual (BAU) to demonstrate the model's superiority.
Liaqat Ali, M. Imran Azim, Jan Peters, Nabin B. Ojha · 10 authors
This paper presents a local energy market (LEM) model to conduct peer-to-peer (P2P) energy trading between a number of participants by dint of the Ethereum-based blockchain technology. The proposed LEM mechanism is structured by considering relevant functional constraints while energy trading is arranged between several participants in the presence of other stakeholders including energy retailer and network operator. LEM participants’ mutual bidding intended P2P trading, actual settlement, and final billing are executed using the smart contracts in Ethereum blockchain to record LEM transactions and related data in an unchangeable and distributed fashion. Lastly, a case study is performed in an Australian suburb with 300 LEM participants, and the simulation results are benchmarked with an existing business-as-usual (BAU)scenario. The simulation results outline that the formulated LEM mechanism 1) reduces the electricity cost of participants remarkably while improving their self-sufficiency, 2) minimises power grid export and import, and 3) retains income margins for the energy retailer and network operator.
Jorge Saldivar, Elena Martínez-Vicente, David Rozas, María Cruz Valiente · 5 authors
Upon its arrival, the Ethereum blockchain promised to introduce a new paradigm of Internet-based applications that would revolutionize multiple fields, from finance to IoT to the public sector. Until now, scientific efforts have been primarily focused on theoretical discussions about the implications of the technology and on technical proposals to improve and consolidate the underlying infrastructure, neglecting the experience of people using blockchain-based systems. However, for this technology to permeate the mainstream, blockchain technology should be easily accessible to the general public. This paper reports on evaluations conducted with first-time blockchain users of two Internet-mediated communities using prototype applications built on Ethereum. Results unveil that even users familiar with technology experienced severe difficulties using blockchain-based apps. Also, we saw how blockchain metaphors and transaction-mediated interactions challenge established mental models for modern applications, imposing heavy workloads on users. We conclude the paper by discussing design implications resulting from blockchain’s paradigm change.
Tom Barbereau, Reilly Smethurst, Orestis Papageorgiou, Johannes Sedlmeir · 5 authors
Ethereum’s public distributed ledger can issue tokenised voting rights that are tradable on crypto-asset exchanges by potentially anyone. Ethereum thus enables global, unincorporated associations to conduct governance experiments. Such experiments are crucial to Decentralised Finance (DeFi). DeFi is a nascent field of unlicensed, unregulated, and non-custodial financial services that utilise public distributed ledgers and crypto-assets rather than corporate structures and sovereign currencies. The inaugural Bloomberg Galaxy DeFi Index, launched in August 2021, included nine Ethereum-based projects – non-custodial exchanges as well as lending and derivatives platforms. Each project is governed, at least in part, by unregistered holders of tokenised voting rights (also known as governance tokens). Token-holders typically vote for or against coders’ improvement proposals that pertain to anything from the allocation of treasury funds to a collateral’s risk parameters. DeFi’s governance thus depends on the distribution and exercise of tokenised voting rights. Since archetypal DeFi projects are not managed by companies or public institutions, not much is known about DeFi’s governance. Regulators and law-makers from the United States recently asked if DeFi’s governance entails a new class of “shadowy” elites. In response, we conducted an exploratory multiple-case study that focused on the tokenised voting rights issued by the nine projects from Bloomberg’s inaugural Galaxy DeFi index. Our mixed methods approach drew on Ethereum-based data about the distribution, trading, staking, and delegation of voting rights tokens, as well as project documentation and archival records. We discovered that DeFi projects’ voting rights are highly concentrated, and the exercise of these rights is very low. Our theoretical contribution is a philosophical intervention: minority rule, not “democracy”, is the probable outcome of token-tradable voting rights and a lack of applicable anti-concentration laws. We interpret DeFi’s minority rule as timocratic.
V. Srikanth, P. Venkata Sai Varma, M. Sunitha, T. Sai Revant · 5 authors
The project involves using Block chain technology and non-fungible tokens (NFTs) to manage assets such as residential, commercial, and agricultural lands. Traditional methods of tracking ownership of these assets require long and complex processes, including the need to obtain title deeds from government offices. The proposed system aims to simplify this process by providing a secure and verifiable way to represent ownership of assets through the use of NFTs and smart contracts on the Ethereum network. This system not only makes it easier to track ownership of assets, but also helps to ensure that assets are properly insured and that regular payments are made for insurance, taxes, and subscriptions like electricity, water, and natural gas. By using NFTs, the system can also represent rare and unique assets that cannot be replicated or replaced, which increases their value and collectability.
Kaustubh Anavkar, Ashish Vishwakarma, Rohit Sardar, Prof. Vivek Pandey
Abstract: A growing number of enterprises, including start-up firms, artistic activities, and charitable causes, are being funded through crowdfunding. Traditional crowdfunding websites, on the other hand, struggle with a variety of issues, including prohibitive pricing, a lack of transparency, and fraud concerns. These issues have led to an increase in the use of blockchain technology as a crowdfunding platform. A decentralized, open-source ledger using blockchain technology safely and permanently records transactions. It provides several advantages for crowdsourcing, including decreased costs, increased transparency, and improved efficiency. Blockchain technology has the potential to open up crowdfunding to a wider range of investors, particularly those in developing countries with limited access to traditional financial institutions. Blockchain technology can be utilised for crowdfunding and smart contracts as well. Numerous procedures associated with crowdfunding, such as fund disbursement and investor verification, can be automated thanks to these self-executing contracts. Automation allows for a significant reduction in administrative work and a faster, more precise crowdfunding procedure. The goal of this article is to advance understanding regarding the application of crowdfunding using blockchain technology. We'll review the body of literature on blockchain and crowdfunding, take into account the benefits and drawbacks of doing so, and offer a framework for implementing blockchain-based crowdfunding. Our study will contribute to the growing body of knowledge on blockchain and crowdfunding, which will be helpful to policymakers, company owners, and investors interested in using blockchain for crowdfunding.
Smart contracts are crucial elements of decentralized technologies, but they face significant obstacles to trustworthiness due to security bugs and trapdoors. To address the core issue, we propose a technology that enables programmers to focus on design-level properties rather than specific low-level attack patterns. Our proposed technology, called Theorem-Carrying-Transaction (TCT), combines the benefits of runtime checking and symbolic proof. Under the TCT protocol, every transaction must carry a theorem that proves its adherence to the safety properties in the invoked contracts, and the blockchain checks the proof before executing the transaction. The unique design of TCT ensures that the theorems are provable and checkable in an efficient manner. We believe that TCT holds a great promise for enabling provably secure smart contracts in the future. As such, we call for collaboration toward this vision.
Sharding scales throughput by splitting blockchain nodes into parallel groups. However, different shards' independent and random scheduling for cross-shard transactions results in numerous conflicts and aborts, since cross-shard transactions from different shards may access the same account. A deterministic ordering can eliminate conflicts by determining a global order for transactions before processing, as proved in the database field. Unfortunately, due to the intertwining of the Byzantine environment and information isolation among shards, there is no trusted party able to predetermine such an order for cross-shard transactions. To tackle this challenge, this paper proposes Prophet, a conflict-free sharding blockchain based on Byzantine-tolerant deterministic ordering. It first depends on untrusted self-organizing coalitions of nodes from different shards to pre-execute cross-shard transactions for prerequisite information about ordering. It then determines a trusted global order based on stateless ordering and post-verification for pre-executed results, through shard cooperation. Following the order, the shards thus orderly execute and commit transactions without conflicts. Prophet orchestrates the pre-execution, ordering, and execution processes in the sharding consensus for minimal overhead. We rigorously prove the determinism and serializability of transactions under the Byzantine and sharded environment. An evaluation of our prototype shows that Prophet improves the throughput by $3.11\times$ and achieves nearly no aborts on 1 million Ethereum transactions compared with state-of-the-art sharding.
Threshold signatures are a fundamental cryptographic primitive used in many practical applications. As proposed by Boneh and Komlo (CRYPTO'22), TAPS is a threshold signature that is a hybrid of privacy and accountability. It enables a combiner to combine t signature shares while revealing nothing about the threshold t or signing quorum to the public and asks a tracer to track a signature to the quorum that generates it. However, TAPS has three disadvantages: it 1) structures upon a centralized model, 2) assumes that both combiner and tracer are honest, and 3) leaves the tracing unnotarized and static. In this work, we introduce Decentralized, Threshold, dynamically Accountable and Private Signature (DeTAPS) that provides decentralized combining and tracing, enhanced privacy against untrusted combiners (tracers), and notarized and dynamic tracing. Specifically, we adopt Dynamic Threshold Public-Key Encryption (DTPKE) to dynamically notarize the tracing process, design non-interactive zero knowledge proofs to achieve public verifiability of notaries, and utilize the Key-Aggregate Searchable Encryption to bridge TAPS and DTPKE so as to awaken the notaries securely and efficiently. In addition, we formalize the definitions and security requirements for DeTAPS. Then we present a generic construction and formally prove its security and privacy. To evaluate the performance, we build a prototype based on SGX2 and Ethereum.
Consumer knowledge of the goods produced or processed by the numerous suppliers and processors is still relatively low due to the growing complexity of the structure of pharmaceutical supply chains. Information asymmetry in the pharmaceutical sector has an effect on welfare, sustainability, and health. (1) Background: In this respect, we wanted to develop a productive structure for a pharmaceutical supply chain that satisfies the consumer information needs and fosters consumer confidence in the pharmacy goods they buy. By using blockchain technology, the main goals were to develop and implement a pharmaceutical supply chain. (2) Objectives: The main objectives of this work were to leverage an Ethereum platform for the development of a tractability system in a pharmaceutical supply chain environment and to analyze the efficiency of MSMAChain with respect to the cost and execution of transactions based on our designed smart contracts. (3) Results: This research looked into a variety of issues related to the value, viability, and effects of blockchain technology for use in supply chain applications. The methods and creations in this environment were monitored and researched. It is vital to identify a number of crucial subjects including future research areas, in order to achieve the widespread acceptance of the supply chain traceability provided by blockchain technology. (4) Conclusions: MSMAChain, an Ethereum blockchain-based approach, leverages smart contracts and decentralized off-chain storage for efficient product traceability in terms of the cost and execution of transaction for a health care supply chain.
Prof. Dr. Pushkar Joglekar, Vedant Parvekar, Aditya Sabde, Omkar K. Rasal · 5 authors
Abstract: The technology that supports bitcoin, known as blockchain, is still in its development. Blockchain technology has the potential to improve existing corporate procedures to make them more collaborative, transparent, secure, and effective.. The banking sector is among the first to take advantage of this technology's disruptive potential. One of the most intricate bank payment systems in the entire globe is the Indian banking system. The current infrastructure that the Indian banking system uses is centralized and based on the real-time gross settlement system. This centralized architecture causes transactions to process slowly and result in wasting. Additionally, it costs a lot for security and recovery considerations. Systems for real-time gross contracts should indeed meet high expectations for speed, stability, and security. The primary objective is to develop a system that provides security, confidentiality, and a decentralized money lending mechanism rather than converting old system to the blockchain platform. Here, a novel strategy that encourages a decentralized system and services built on the Ethereum blockchain is progressed. The system enables a number of services using distributed ledger technology, including loan checking, money transfer, and money deposit, among others.
In August of 2022, the United States Department of Treasury sanctioned the virtual currency mixer Tornado Cash, an open-source and fully decentralised piece of software running on the Ethereum blockchain, subsequently leading to the arrest of one of its developers in the Netherlands. Not only was this the first time the Office of Foreign Assets Control (OFAC) extended its authority to sanction a foreign ‘person’ to software, but the decentralised nature of the software and global usage highlight the challenge of establishing jurisdiction over decentralised software and its global user base. The government claims jurisdiction over citizens, residents, and any assets that pass through the country’s territory. As a global financial center with most large tech companies, this often facilitates the establishment of jurisdiction over global conduct that passes through US servers. However, decentralised programs on blockchains with nodes located around the world challenge this traditional approach as either nearly all countries can claim jurisdiction over users, subjecting users to criminal laws in countries with which they have no true interaction, or they limit jurisdiction, thereby risking abuse by bad actors. This article takes a comparative approach to examine the challenges to establishing criminal jurisdiction on cryptocurrency-related crimes.
Nowadays with the rising number of personal vehicles, finding a parking space has become an issue for many residents.Advancements in technologies like Internet of Things (IoT) have helped to maximize the productivity and reliability of urban infrastructure.In this paper, we propose an online parking rent system to reserve a parking space for the residents and other users, via a blockchain on the Ethereum platform which uses a non-fungible token as currency and a barcode for ease of use.A barcode will be provided while reserving the parking space, and is used when unlocking the bollards.This will help residents to save time by knowing their parking spot.
Real-time and vision-based quality control for industrial processes has drawn great interest from both scientists and practitioners, particularly following the transition to Zero Defect Manufacturing (ZDM) and Industry 4.0. Despite considerable progress, most ZDM approaches focus on the accuracy of the inspection process, often neglecting critical factors for application in the shop floor. On one hand, near real-time methods are needed for early defect detection and containment. On the other hand, data scarcity is an issue causing AI methods to overfit. Another concern is the accountability of AI results, since even if an AI pipeline is successfully deployed, its predictions are not verifiable in the long term. In this work, we explore a real-time solution based on lightweight Deep Residual Networks and Blockchain technology to address these issues. Concretely, we propose a two-phase training strategy to boost the performance of baseline classifiers while maintaining low inference times. The performance of the proposed methodology is presented in two different industrial use cases with strict timing requirements, one concerning battery assembly line and the other antenna manufacturing. We validate the proposed method for defect detection and compare the results with common training strategies demonstrating an improvement of 3% and 10% in F1-score and accuracy on the two cases respectively, while lowering inference time by 2.2× compared to existing light architectures. Contributing to the accountability of AI results, we present an IoT framework using Blockchain deployed in Private Ethereum.
Abstract: The foundation of e-commerce is based on conducting transactions and transferring goods online without the need for physical travel. However, cyber threats can pose a risk when it comes to transferring transactional data. Our primary goal is to develop a system that can protect against such mishaps during the process of transmitting transactional data. Additionally, we aim to implement an automated system that ensures error-free transactions. To achieve these objectives, we will leverage the latest technologies such as blockchain and smart contracts. Blockchain technology provides a decentralized and immutable digital ledger that can securely store and transfer data across a network. E-commerce can use blockchain technology to process transactions safely, securely, and rapidly. By using blockchain technology, we can enable peer-to-peer transaction systems and data encryption, ensuring the safe transfer of sensitive financial information. Moreover, we can use blockchain technology to transfer transactional data securely. A smart contract is a specialized program that functions as an agreement and runs on the Ethereum blockchain. Smart contracts provide transactional security, and when combined with blockchain technology, they can transform e-commerce. By utilizing blockchain technology to ensure data security and user privacy and smart contracts to maintain the transaction protocol, our proposed system aims to offer a solution for transactional data privacy and transparency. In conclusion, our system will provide a secure and transparent platform for conducting e-commerce transactions. With the use of blockchain technology and smart contracts, we can create a system that ensures safe transfer of data and error-free transactions.
Farida Habib Semantha, Sami Azam, Bharanidharan Shanmugam, Kheng Cher Yeo
Privacy in Electronic Health Records (EHR) has become a significant concern in today’s rapidly changing world, particularly for personal and sensitive user data. The sheer volume and sensitive nature of patient records require healthcare providers to exercise an intense quantity of caution during EHR implementation. In recent years, various healthcare providers have been hit by ransomware and distributed denial of service attacks, halting many emergency services during COVID-19. Personal data breaches are becoming more common day by day, and privacy concerns are often raised when sharing data across a network, mainly due to transparency and security issues. To tackle this problem, various researchers have proposed privacy-preserving solutions for EHR. However, most solutions do not extensively use Privacy by Design (PbD) mechanisms, distributed data storage and sharing when designing their frameworks, which is the emphasis of this study. To design a framework for Privacy by Design in Electronic Health Records (PbDinEHR) that can preserve the privacy of patients during data collection, storage, access and sharing, we have analysed the fundamental principles of privacy by design and privacy design strategies, and the compatibility of our proposed healthcare principles with Privacy Impact Assessment (PIA), Australian Privacy Principles (APPs) and General Data Protection Regulation (GDPR). To demonstrate the proposed framework, ‘PbDinEHR’, we have implemented a Patient Record Management System (PRMS) to create interfaces for patients and healthcare providers. In addition, to provide transparency and security for sharing patients’ medical files with various healthcare providers, we have implemented a distributed file system and two permission blockchain networks using the InterPlanetary File System (IPFS) and Ethereum blockchain. This allows us to expand the proposed privacy by design mechanisms in the future to enable healthcare providers, patients, imaging labs and others to share patient-centric data in a transparent manner. The developed framework has been tested and evaluated to ensure user performance, effectiveness, and security. The complete solution is expected to provide progressive resistance in the face of continuous data breaches in the patient information domain.
Context: Smart contracts are computerized self-executing contracts that contain clauses, which are enforced once certain conditions are met. Smart contracts are immutable by design and cannot be modified once deployed, which ensures trustlessness. Despite smart contracts' immutability benefits, upgrading contract code is still necessary for bug fixes and potential feature improvements. In the past few years, the smart contract community introduced several practices for upgrading smart contracts. Upgradeable contracts are smart contracts that exhibit these practices and are designed with upgradeability in mind. During the upgrade process, a new smart contract version is deployed with the desired modification, and subsequent user requests will be forwarded to the latest version (upgraded contract). Nevertheless, little is known about the characteristics of the upgrading practices, how developers apply them, and how upgrading impacts contract usage. Objectives: This paper aims to characterize smart contract upgrading patterns and analyze their prevalence based on the deployed contracts that exhibit these patterns. Furthermore, we intend to investigate the reasons why developers upgrade contracts (e.g., introduce features, fix vulnerabilities) and how upgrades affect the adoption and life span of a contract in practice. Method: We collect deployed smart contracts metadata and source codes to identify contracts that exhibit certain upgrade patterns (upgradeable contracts) based on a set of policies. Then we trace smart contract versions for each upgradable contract and identify the changes in contract versions using similarity and vulnerabilities detection tools. Finally, we plan to analyze the impact of upgrading on contract usage based on the number of transactions received and the lifetime of the contract version.
Michael Rodler, David Paaßen, Wenting Li, Lukas Bernhard · 7 authors
Smart contracts are increasingly being used to manage large numbers of high-value cryptocurrency accounts. There is a strong demand for automated, efficient, and comprehensive methods to detect security vulnerabilities in a given contract. While the literature features a plethora of analysis methods for smart contracts, the existing proposals do not address the increasing complexity of contracts. Existing analysis tools suffer from false alarms and missed bugs in today's smart contracts that are increasingly defined by complexity and interdependencies. To scale accurate analysis to modern smart contracts, we introduce EF/CF, a high-performance fuzzer for Ethereum smart contracts. In contrast to previous work, EF/CF efficiently and accurately models complex smart contract interactions, such as reentrancy and cross-contract interactions, at a very high fuzzing throughput rate. To achieve this, EF/CF transpiles smart contract bytecode into native C++ code, thereby enabling the reuse of existing, optimized fuzzing toolchains. Furthermore, EF/CF increases fuzzing efficiency by employing a structure-aware mutation engine for smart contract transaction sequences and using a contract's ABI to generate valid transaction inputs. In a comprehensive evaluation, we show that EF/CF scales better -- without compromising accuracy -- to complex contracts compared to state-of-the-art approaches, including other fuzzers, symbolic/concolic execution, and hybrid approaches. Moreover, we show that EF/CF can automatically generate transaction sequences that exploit reentrancy bugs to steal Ether.
Aggelos Kiayias, Ηλίας Κουτσουπιάς, Philip Lazos, Giorgos Panagiotakos
Blockchain systems come with the promise of being inclusive for a variety of decentralized applications (DApps) that can serve different purposes and have different urgency requirements. Despite this, the transaction fee mechanisms currently deployed in popular platforms as well as previous modeling attempts for the associated mechanism design problem focus on an approach that favors increasing prices in favor of those clients who value immediate service during periods of congestion. To address this issue, we introduce a model that captures the traffic diversity of blockchain systems and a tiered pricing mechanism that is capable of implementing more inclusive transaction policies. In this model, we demonstrate formally that EIP-1559, the transaction fee mechanism currently used in Ethereum, is not inclusive and demonstrate experimentally that its prices surge horizontally during periods of congestion. On the other hand, we prove formally that our mechanism achieves stable prices in expectation and we provide experimental results that establish that prices for transactions can be kept low for low urgency transactions, resulting in a diverse set of transaction types entering the blockchain. At the same time, perhaps surprisingly, our mechanism does not necessarily sacrifice revenue since the lowering of the prices for low urgency transactions can be covered from high urgency ones due to the price discrimination ability of the mechanism.
Social recovery schemes enable the recovery of decentralized digital assets like Bitcoin and Ethereum through a social network. These schemes suffer from security issues and limitations including centralization, a conspiracy of one's network, large transaction fees for the user and network, and verifiable connections between the user and the network. To mitigate these issues, the work proposes and implements a novel social recovery scheme based on verifiable secret sharing, smart contract code, encrypted communication, and biometric encryption. The security and performance analysis versus key existing implementations is evaluated in terms of security features and gas fees.
Open access
Blockchain Technology Applications and Security
Advanced Steganography and Watermarking Techniques
As the price of virtual currency fluctuates greatly, precise prediction and appropriate trading strategies can bring investors best returns. This paper predicted the price of Ethereum and Bitcoin in the light of autoregressive integrated moving average model (ARIMA) and get a R2 of 0.995 and 0.993 respectively, which indicates the model can yield reasonable predictions. Then their investment ratios are set to 0.88 and 1.12 respectively by analytic hierarchy process (AHP). Particle swarm optimization (PSO) is used to solve the daily revenue function formed by the predicted price and the current price. Finally, the paper compared the returns yielded by the PSO trading strategy optimized by AHP and the strategy without optimization. It can be concluded that the AHP has a possibility of 64.66 per cent to yield more returns when used.
Chekwube V. Madichie, Franklin N. Ngwu, Eze A. Eze, Olisaemeka D. Maduka
Cryptocurrencies have, over the years, gained an unprecedented prominence in financial discourse, with the market fielding over 5,300 digital currencies and reaching over $2 trillion in market capitalisation in 2022. The surge in market values of digital currencies and their popularity in the world of e-commerce have remained unabated and equally received special attention from researchers focusing on identifying the underlying factors that drive changes in their market values. Thus, this study models the dynamics of the prices of cryptocurrencies alongside their interconnectedness, focusing on Bitcoin, Ethereum, and Litecoin along the time and frequency dimensions of monthly data from 1 March 2016 to 05/31/2022. Based on the ARDL model, results show that the volume of transactions of Bitcoin, Ethereum, and Litecoin, oil prices, and gold prices exert a more significant positive influence on their prices in the longrun than in the shortrun. However, the publicity of the selected cryptocurrencies (google search rates) does not significantly influence their prices. Interestingly, results from the Wavelet Granger causality tests show no causality between the raw series of Bitcoin, Ethereum, and Litecoin prices. However, a bi-directional causality exists between Bitcoin and Ethereum prices during the longrun in their low frequencies, a unidirectional causality running from Bitcoin to Litecoin prices during the longrun in their low frequencies, and a unidirectional causality running from Litecoin to Ethereum prices during the shortrun, medium run and longrun in their high, medium, and low frequencies. These findings have profound implications for the global financial market and investor decisions.
Farhan Shikalgar, Farhaan Khan, Saud Kadiri, Anas Khan
Improving efficiency and performance is an important topic in the world today. As it is well-known, cooperative computing is an effective and traditional approach, and it is widely used in various fields. Inspired by this idea, take E- commerce for example, Security is one of its important indicators. In E-commerce, the security technology has become a major issue restricting the rapid development and popularization of E- commerce.With the advent of new technologies, Blockchain plays a major role in ecommerce sector.With the characteristics of decentralization, persistency, anonymity and auditability, blockchain technology is a new tool to solve the product traceability, information security and privacy, payment efficiency and cost reduction in cross- border e-business.Existing E-commerce models are trapped in a dilemma between the proof of ownership and privacy protection. To address this issue,We have made a platform Shoppingverse which is a blockchain based ecommerce.we design a privacy-preserving business protocol by employing private smart contracts in the negotiation phase. The protocol allows counterparties make deals without the disclosure of private information such as identities, addresses, and phone numbers. Moreover, we employ the zero- knowledge proof to guarantee the ownership. Key Words: Ethereum, Blockchain, Ecommerce, Smart Contract.