Block Verification Mechanism Based on Zero-Knowledge Proof in Blockchain

Since transactions in blockchain are based on public ledger verification,this raises security concerns about privacy protection.And it will cause the accumulation of data on the chain and resulting in the low efficiency of block verification,when the whole transaction on the chain is verified.In order to improve the efficiency and privacy protection of block data verification,this paper proposes an efficient block verification mechanism with privacy protection based on zeroknowledge proof(ZKP),which not only protects the privacy of users but also improves the speed of data block verification.There is no need to put the whole transaction on the chain when verifying block data.It just needs to generate the ZKP and root hash with the transaction information,then save them to the smart contract for verification.Moreover,the ZKP verification in smart contract is carried out to realize the privacy protection of the transaction and efficient verification of the block.When the data is validated,the buffer accepts the complete transaction,updates the transaction status in the cloud database,and packages up the chain.So,the ZKP strengthens the privacy protection ability of blockchain,and the smart contracts save the time cost of block verification.

Memorizable Interactive Proof and Zero-Knowledge Proof Systems

Interactive proof and zero-knowledge proof systems are two important concepts in cryptography and complexity theory. In the past two decades, a great number of interactive proof and zero-knowledge proof protocols have been designed and applied in practice. In this paper, a simple memorizable zero-knowledge protocol is proposed for graph non-isomorphism problem, based on the memorizable interactive proof system, which is extended from the original definition of interactive proof and is more applicable in reality. Keywords interactive proof - zero-knowledge proof - memorizable interactive proof - memorizable zero-knowledge proof This work was supported by the ministry of Science and Technology of China (Grant No.2001CCA03000), and the National Natural Science Foundation of China (Grant No.60273045).Ning Chen received his B.S. degree from Fudan University in 2001. Now he is a master candidate of Department of Computer Science, Fudan University. His research interests include computational complexity, computational cryptography, algorithm design and analysis.Jia-Wei Rong received her B.S. degree from Fudan University in 2002. Now she is a master candidate of Department of Computer Science, Fudan University. Her research interests include computational cryptography, machine learning, artificial intelligence.

BMSC:A Novel Anonymous Trading Scheme Based on Zero-Knowledge Proof in Ethereum

Blockchains are widely used because of their openness,transparency,nontampering and decentralization.However,there is a high risk of information leakage when trading on blockchain,and the existing anonymous trading schemes still have some problems.To meet the high requirement of anonymity,the cost of proof submitted by the user is too large,which does not apply to blockchain storage.Meanwhile,transaction verification takes too long to ensure the legitimacy of the transaction.To solve these problems,this paper presents a novel anonymous trading scheme named Block Maze Smart Contract(BMSC)based on the zeroknowledge proof system zk-SNARKs to propose efficiency.This scheme can hide account balances,transaction amounts,and the transfer relationships between transaction parties while preventing overspending attacks and double-spending attacks.Compared with other anonymous schemes,this scheme has less cost of proof and takes less time for transaction verification while meeting the high requirements of anonymity and security.

Privacy-preserving analytics for the securitization market: a zero-knowledge distributed ledger technology application

A zero-knowledge proof or protocol is a cryptographic technique for verifying private data without revealing it in its clear form.In this paper,we evaluate the potential for zero-knowledge distributed ledger technology to alleviate asymmetry of information in the asset-backed securitization market.To frame this inquiry,we conducted market data analyses,a review of prior literature,stakeholder interviews with investors,originators and security issuers and collaboration with blockchain engineers and researchers.We introduce a new system which could enable all market participants in the securitization lifecycle(e.g.investors,rating agencies,regulators and security issuers)to interact on a unique decentralized platform while maintaining the privacy of loan-level data,therefore providing the industry with timely analytics and performance data.Our platform is powered by zkLedger(Narula et al.2018),a zero-knowledge protocol developed by the MIT Media Lab and the first system that enables participants of a distributed ledger to run publicly verifiable analytics on masked data.

Blockchain-based continuous data integrity checking protocol with zero-knowledge privacy protection

The cloud computing technology has emerged,developed,and matured in recent years,consequently commercializing remote outsourcing storage services.An increasing number of companies and individuals have chosen the cloud to store their data.However,accidents,such as cloud server downtime,cloud data loss,and accidental deletion,are serious issues for some applications that need to run around the clock.For some mission and business-critical applications,the continuous availability of outsourcing storage services is also necessary to protect users'outsourced data during downtime.Nevertheless,ensuring the continuous availability of data in public cloud data integrity auditing protocols leads to data privacy issues because auditors can obtain the data content of users by a sufficient number of storage proofs.Therefore,protecting data privacy is a burning issue.In addition,existing data integrity auditing schemes that rely on semi-trusted third-party auditors have several security problems,including single points of failure and performance bottlenecks.To deal with these issues,we propose herein a blockchain-based continuous data integrity checking protocol with zero-knowledge privacy protection.We realize a concrete construction by using a verifiable delay function with high efficiency and proof of retrievability,and prove the security of the proposal in a random oracle model.The proposed construction supports dynamic updates for the outsourced data.We also design smart contracts to ensure fairness among the parties involved.Finally,we implement the protocols,and the experimental results demonstrate the efficiency of the proposed protocol.

A Leaking-Proof Theranostic Nanoplatform for Tumor-Targeted and Dual-Modality Imaging-Guided Photodynamic Therapy

Objective:A protein-based leaking-proof theranostic nanoplatform for dual-modality imaging-guided tumor photodynamic therapy(PDT)has been designed.Impact Statement:A site-specific conjugation of chlorin e6(Ce6)to ferrimagnetic ferritin(MFtn-Ce6)has been constructed to address the challenge of unexpected leakage that often occurs during small-molecule drug delivery.Introduction:PDT is one of the most promising approaches for tumor treatment,while a delivery system is typically required for hydrophobic photosensitizers.However,the nonspecific distribution and leakage of photosensitizers could lead to insufficient drug accumulation in tumor sites.Methods:An engineered ferritin was generated for site-specific conjugation of Ce6 to obtain a leaking-proof delivery system,and a ferrimagnetic core was biomineralized in the cavity of ferritin,resulting in a fluorescent ferrimagnetic ferritin nanoplatform(MFtn-Ce6).The distribution and tumor targeting of MFtn-Ce6 can be detected by magnetic resonance imaging(MRI)and fluorescence imaging(FLI).Results:MFtn-Ce6 showed effective dual-modality MRI and FLI.A prolonged in vivo circulation and increased tumor accumulation and retention of photosensitizer was observed.The time-dependent distribution of MFtn-Ce6 can be precisely tracked in real time to find the optimal time window for PDT treatment.The colocalization of ferritin and the iron oxide core confirms the high stability of the nanoplatform in vivo.The results showed that mice treated with MFtn-Ce6 exhibited marked tumor-suppressive activity after laser irradiation.Conclusion:The ferritin-based leaking-proof nanoplatform can be used for the efficient delivery of the photosensitizer to achieve an enhanced therapeutic effect.This method established a general approach for the dual-modality imagingguided tumor delivery of PDT agents.

A Cloud-Fog Enabled and Privacy-Preserving IoT Data Market Platform Based on Blockchain

The dynamic landscape of the Internet of Things(IoT)is set to revolutionize the pace of interaction among entities,ushering in a proliferation of applications characterized by heightened quality and diversity.Among the pivotal applications within the realm of IoT,as a significant example,the Smart Grid(SG)evolves into intricate networks of energy deployment marked by data integration.This evolution concurrently entails data interchange with other IoT entities.However,there are also several challenges including data-sharing overheads and the intricate establishment of trusted centers in the IoT ecosystem.In this paper,we introduce a hierarchical secure data-sharing platform empowered by cloud-fog integration.Furthermore,we propose a novel non-interactive zero-knowledge proof-based group authentication and key agreement protocol that supports one-to-many sharing sets of IoT data,especially SG data.The security formal verification tool shows that the proposed scheme can achieve mutual authentication and secure data sharing while protecting the privacy of data providers.Compared with previous IoT data sharing schemes,the proposed scheme has advantages in both computational and transmission efficiency,and has more superiority with the increasing volume of shared data or increasing number of participants.

A Fair and Trusted Trading Scheme for Medical Data Based on Smart Contracts

Data is regarded as a valuable asset,and sharing data is a prerequisite for fully exploiting the value of data.However,the current medical data sharing scheme lacks a fair incentive mechanism,and the authenticity of data cannot be guaranteed,resulting in low enthusiasm of participants.A fair and trusted medical data trading scheme based on smart contracts is proposed,which aims to encourage participants to be honest and improve their enthusiasm for participation.The scheme uses zero-knowledge range proof for trusted verification,verifies the authenticity of the patient’s data and the specific attributes of the data before the transaction,and realizes privacy protection.At the same time,the game pricing strategy selects the best revenue strategy for all parties involved and realizes the fairness and incentive of the transaction price.The smart contract is used to complete the verification and game bargaining process,and the blockchain is used as a distributed ledger to record the medical data transaction process to prevent data tampering and transaction denial.Finally,by deploying smart contracts on the Ethereum test network and conducting experiments and theoretical calculations,it is proved that the transaction scheme achieves trusted verification and fair bargaining while ensuring privacy protection in a decentralized environment.The experimental results show that the model improves the credibility and fairness of medical data transactions,maximizes social benefits,encourages more patients and medical institutions to participate in the circulation of medical data,and more fully taps the potential value of medical data.

A Comparative Analysis of the New -3(-n) - 1 Remer Conjecture and a Proof of the 3n + 1 Collatz Conjecture

This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true.

A Proof of Brouwer’s Fixed Point Theorem Using Sperner’s Lemma

This article offers a simple but rigorous proof of Brouwer’s fixed point theorem using Sperner’s Lemma.The general method I have used so far in the proof is mainly to convert the n-dimensional shapes to the corresponding case under the Sperner’s Labeling and apply the Sperner’s Lemma to solve the question.

“互联网+泛在感知”教学模式的探索与尝试

近年来,以“互联网+”为代表的信息技术与高校课程教学相结合,展现出巨大的技术优越性和教学应用价值。本研究将“互联网+”与机械制图教学相结合,分析了数字化设计制造背景下机械制图的内涵与发展;将“互联网+”大数据精确分析与传统线下授课的严谨灵活相结合,提出了机械制图课程的“互联网+泛在感知”教学模式,并在教学实践中对其有效性进行了检验。结果表明,“互联网+泛在感知”教学模式充分发挥了互联网优势,能够有效发现知识漏洞,有针对性地进行知识主动推送,并提高知识掌握程度,是对机械制图课程教学与信息技术深度融合的有益探索和尝试。

论环境民事公益诉讼中因果关系要件的证明

当前,环境民事公益诉讼中因果关系要件的证明责任如何分配及其证明标准如何设定,对此理论界和实务界仍有很大争议。在证明责任分配问题上,解决路径在于参照适用《民法典》第一千二百三十条的规定,由被告承担环境民事公益诉讼中因果关系要件的客观证明责任。与此同时,原告需提供能够证明关联性事实的初步证据。这一规则应当理解为因果关系的法律推定。将因果关系法律推定规则引入环境民事公益诉讼中具有合理性基础,如纠正人们对环境侵权因果关系要件“证明责任倒置”的错误认识、防止原告滥用诉权、平衡原被告双方的举证负担。在证明标准问题上,环境民事公益诉讼中因果关系要件的证明标准应因事后救济性环境民事公益诉讼和预防性环境民事公益诉讼的类型划分而有所区别,且受关联性事实认定标准的影响。

新时期刑事印证证明的误解与澄清

印证是从属于自由心证的证明过程,既无法涵盖所有的犯罪类型,也无法适用于所有的待证事实,故无法成为与法定证明、自由证明相并列的一类新模式。但作为方法,印证证明仍然具有重要地位,实践中被广泛诟病的虚假印证、误解印证等不符合印证要求,故冤假错案也不能归咎于印证本身。实践中,印证证明与证明标准混同的问题突出,事实上二者之间既有联系又有区别,呈现方法和目的的关系,方法自然不同于目的,但方法是达成目的的手段,目的是方法努力的终点。因此,尽管印证具有提升裁判者心证的积极意义,但不能人为拔高至证明模式的程度,在实践中既要反对意图抛弃印证的“冤假错案成因论”,也要反对过度崇尚印证的“证明标准等同论”。

区块链隐私众包中的数据验证与可控匿名方案

针对隐私众包场景下出现的数据验证、匿名作恶检测和跨平台资源交互等需求,该文基于区块链技术,并结合零知识证明与环签名技术,提出一种联盟链架构下的隐私众包方案。该方案依靠零知识证明实现对加密数据的验证,依靠链接可撤销环签名改进方案实现工人身份的可控匿名,引入联盟链架构实现众包实体之间的资源交互。在完成众包完整流程的同时,实现隐私众包所需的数据保护与身份保护。安全性分析表明,该方案具有隐私性、可验证性、可控匿名性与公平性。实验结果验证了方案在效率与性能方面的有效性。

位移无拖曳控制的动力学协调条件研究

针对位移无拖曳控制的可实现性问题及避免推力饱和问题,首先基于位移无拖曳控制动力学方程,推导出位移无拖曳控制系统中连续可变推力推进子系统的最大推力需要满足的基本动力学协调条件。进一步由位移无拖曳控制动力学方程退化得到的切换动力学方程,推导出负刚度加速度函数为线性及非线性函数两种情形下的让步动力学协调条件。针对让步动力学协调条件开展了仿真比对,结果表明,强非线性情形下的让步动力学协调条件比退化的线性情形更加严苛。最后通过分析给出位移无拖曳控制避免推力饱和的、定性的动力学协调条件,并得到仿真校验,即:检验质量初始状态及指令状态应在让步动力学协调条件区域内靠近负刚度力零位,开环系统时间延迟尽可能短,并且控制带宽应折中选择。

刑事案件事实认定中经验法则的运用

经验法则是证据评价的依据、建立证据与事实之间联系的桥梁以及事实认定合理性的检验标准,在刑事案件事实认定中经验法则的运用不可或缺。经验法则的适当选取是其规范运用的前提和基础,对于指向一致的经验法则应以盖然性程度为选取的基准,而内容迥异的经验法则则以具体条件的符合性为选取标准。裁判文书应当展示经验法则的内容,并结合案件的事实与证据论证经验法则选取的准确性与运用的合理性;对于控辩双方援引的经验法则,裁判文书应区别情况选择回应的方式,以增强裁判结论的正当性。对于经验法则运用的错误,可以通过启动第二审程序、审判监督程序实现救济。经验法则的规范运用有赖于控辩双方运用经验法则的公开与论辩、人民陪审员制度功能的充分发挥、直接审理原则的彻底贯彻等程序支撑规则。

基于字合成运算的标签组群组共存证明协议

针对现有的大多数证明协议无法同时证明多标签同时存在缺陷,提出一种具有可扩展性的电子标签组证明协议。协议采用按位运算设计实现的字合成运算对信息加密,字合成运算可使得协议达到超轻量级计算;同时字合成运算实现中巧妙运用参数自身具备的汉明重量,可减少参量引入;协议基于先验证再响应机制,可抵抗假冒攻击等。对协议进行不同角度分析,表明协议能够提供较高的安全性能,同时能够适用于现有低成本被动式电子标签系统中。

医药领域知识产权诉讼举证的研究

药品的专利保护问题是医药领域知识产权保护的一项重要内容,一直备受关注。探讨医药领域知识产权诉讼举证的问题具有重要意义。举证是医药领域专利诉讼中的关键因素。本文从普适性的诉讼举证规则出发,陈述由原告和被告承担的举证内容,步步深入,探讨涉及医药领域方法类专利的举证责任倒置问题,分析其中的关键措施或方法。归结认为举证规则的运用及其运用是否得当与医药专利能否获得保护以及是否得到最充分的保护这一结果密切相关。

中国式刑事证明结构:分段包干与选择性接力

1979年颁行的《刑事诉讼法》确立了我国分段包干与选择性接力的证明结构。它既体现在侦诉审关系中,也体现在上下审关系中。在这一结构中,公检法在各自主导的诉讼阶段只有调查程序和方式的差异,并无查证责任和目标的差异。后端办案机关有接力查证的责任。接力者具有依照法定证明标准选择是否接力的判断权,也有选择接力主体、范围和方法的裁量权。《刑事诉讼法》虽然历经多次修改,但均朝着优化结构的方向前行。我国刑事证明结构具有如下鲜明特色:一是事实认定权力的去中心主义,二是专门机关查证责任的同质化,三是查证范围认定权的单元化,四是“调查”真相演变为“接着查”真相,五是作为查明真相协助者的辩方。