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.

Group Signature Based on Non-interactive Zero-Knowledge Proofs

Non-Interactive Zero-Knowledge(NIZK for short) proofs are fascinating and extremely useful in many security protocols. In this paper,a new group signature scheme,decisional linear assumption group signature(DLAGS for short) with NIZK proofs is proposed which can prove and sign the multiple values rather than individual bits based on DLIN assumption. DLAGS does not need to interact between the verifier and issuer,which can decrease the communication times and storage cost compared with the existing interactive group signature schemes. We prove and sign the blocks of messages instead of limiting the proved message to only one bit(0 or 1) in the conventional non-interactive zero-knowledge proof system,and we also prove that our scheme satisfy the property of anonymity,unlinkability and traceability. Finally,our scheme is compared with the other scheme(Benoitt's scheme) which is also based on the NIZK proofs system and the DLIN assumption,and the results show that our scheme requires fewer members of groups and computational times.

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.

Existence of 3-round zero-knowledge proof systems for NP

This paper considers the existence of 3-round zero-knowledge proof systems for NP. Whether there exist 3-round non-black-box zero-knowledge proof systems for NP language is an open problem. By introducing a new interactive proof model, we construct a 3-round zero-knowledge proof system for graph 3-coloring under standard assumptions. Our protocol is a non-black-box zero-knowledge proof because we adopt a special strategy to prove the zero-knowledge property. Consequently, our construction shows the existence of 3-round non-black-box zero-knowledge proof for all languages in NP under the DDH assumption.

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 Blockchain-Based Proxy Re-Encryption Scheme with Conditional Privacy Protection and Auditability

With the development of Internet of Things technology,intelligent door lock devices are widely used in the field of house leasing.In the traditional housing leasing scenario,problems of door lock information disclosure,tenant privacy disclosure and rental contract disputes frequently occur,and the security,fairness and auditability of the housing leasing transaction cannot be guaranteed.To solve the above problems,a blockchain-based proxy re-encryption scheme with conditional privacy protection and auditability is proposed.The scheme implements fine-grained access control of door lock data based on attribute encryption technology with policy hiding,and uses proxy re-encryption technology to achieve auditable supervision of door lock information transactions.Homomorphic encryption technology and zero-knowledge proof technology are introduced to ensure the confidentiality of housing rent information and the fairness of rent payment.To construct a decentralized housing lease transaction architecture,the scheme realizes the efficient collaboration between the door lock data ciphertext stored under the chain and the key information ciphertext on the chain based on the blockchain and InterPlanetary File System.Finally,the security proof and computing performance analysis of the proposed scheme are carried out.The results show that the scheme can resist the chosen plaintext attack and has low computational cost.

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 Blockchain-Based Efficient Cross-Domain Authentication Scheme for Internet of Vehicles

The Internet of Vehicles(IoV)is extensively deployed in outdoor and open environments to effectively address traffic efficiency and safety issues by connecting vehicles to the network.However,due to the open and variable nature of its network topology,vehicles frequently engage in cross-domain interactions.During such processes,directly uploading sensitive information to roadside units for interaction may expose it to malicious tampering or interception by attackers,thus compromising the security of the cross-domain authentication process.Additionally,IoV imposes high real-time requirements,and existing cross-domain authentication schemes for IoV often encounter efficiency issues.To mitigate these challenges,we propose CAIoV,a blockchain-based efficient cross-domain authentication scheme for IoV.This scheme comprehensively integrates technologies such as zero-knowledge proofs,smart contracts,and Merkle hash tree structures.It divides the cross-domain process into anonymous cross-domain authentication and safe cross-domain authentication phases to ensure efficiency while maintaining a balance between efficiency and security.Finally,we evaluate the performance of CAIoV.Experimental results demonstrate that our proposed scheme reduces computational overhead by approximately 20%,communication overhead by around 10%,and storage overhead by nearly 30%.

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.

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”。

矿井无线电波防爆安全发射功率研究

5G,5.5G,WiFi6,WiFi7,UWB,ZigBee等矿井移动通信系统及人员和车辆定位系统等发射的大功率无线电波有点燃瓦斯和煤尘的风险。因此,需要合理设置防爆无线电设备发射的无线电波防爆安全功率阈值,限制防爆无线电设备发射的无线电波功率。欧洲标准CLC/TR 50427:2004《Assessment of inadvertent ignition of flammable atmospheres by radio-frequency radiation-Guide》规定了爆炸性气体环境中无线电波防爆安全接收点火功率阈值,但缺少无线电波防爆安全发射功率阈值的内容。国家标准GB/T 3836.1—2021《爆炸性环境第1部分:设备通用要求》和国际标准IEC 60079-0:2017《Explosive atmospheres-Part 0:Equipment-General requirements》虽然有无线电波防爆安全发射功率阈值的相关规定,但错误地将欧洲标准CLC/TR 50427:2004中的无线电波防爆安全接收点火功率阈值修改为无线电波防爆安全发射功率阈值,大大降低了爆炸性环境中无线电设备所能允许的最大发射功率。由于煤矿井下没有能作为接收天线的起重机这类细长结构物体,且现有矿井无线通信及定位系统工作频率均远大于30 MHz,所以,无线电波防爆安全接收点火功率阈值应为8 W,而不是国家标准GB/T 3836.1—2021和国际标准IEC 60079-0:2017规定的无线电波防爆安全发射功率阈值6 W。在发射天线发射的无线电波能量全部被等效天线吸收的最不利于无线电防爆的传输和耦合情况下,无线电设备工作频率为等效天线谐振频率时,接收点火功率达到最大,为等效天线接收的总功率的一半,即发射功率的一半。在实际工程中,无线传输效率和耦合效率均不会为1,因此,无线电波防爆安全发射功率阈值应是无线电波防爆安全接收点火功率阈值2倍以上。煤矿井下无线电波防爆安全接收点火功率阈值为8 W,因此,煤矿井下无线电波防爆安全发射功率阈值应大于16 W。

刑事抽样证明扩张适用的风险及防控

为应对网络犯罪海量证据运用与罪量证明难题,司法解释扩张了刑事抽样证明的适用范围。这种扩张适用主要表现为从法定的特殊犯罪拓展为具有海量证据的犯罪,从实物证据扩张至部分言词证据,从控诉方延伸至辩护方。然而,在相关规则尚不完备的情况下,易出现过度减轻控诉方的证明义务,不当加重辩护方的辩护负担,大幅增加审判方的裁判错误等风险。鉴此,应系统建构风险防控的技术与法律机制。在技术方面,抽样总体满足数量与同质性要求,抽样样本量采用数量和比例相结合的判定标准,抽样方法应当具有可靠性。在法律方面,建立健全刑事抽样证明适用必要性的司法审查机制,明确规定刑事抽样证明主体的抽样开示义务,严格要求刑事抽样证明必须达到排除合理怀疑标准。

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。

防爆5G微基站研发及其在石化企业的应用

随着无线通信技术、超大规模集成电路技术的发展,无线移动通信在数年内从2G模拟阶段到3G、4G、5G数字阶段的数次跃迁,目前5G无线移动通信网络实现了民用场景全面覆盖。但是在油气开采、炼油、化工等易燃易爆工业现场受防爆条件的限制,5G无线移动通信网络覆盖推进困难,边缘计算、网络切片、物联网等新技术、新应用无法实现部署。本文所述通过研发设计防爆5G微基站,实现在工业危险环境部署5G无线移动通信网络,推进新技术在石化企业落地应用,助力石化企业提质增效,为我国石化行业的智能化、智慧化提供高效、稳定的无线网络保障。