区块链技术对人工智能的影响

区块链是比特币的支撑技术,具有去中心化、不可篡改、可追溯的特点,在金融、数字版权、公证、物联网、文档存储等领域开始逐步应用并取得了较大成果,已成为与人工智能、大数据、云计算等比肩的热门技术。人工智能建立在海量数据和强大计算力的基础上,区块链技术的特点可以很好地融入到人工智能应用中,从而推动人工智能的进一步发展。文中在介绍了区块链基本概念与工作机制的基础上,重点介绍区块链技术的发展对人工智能的影响,分析了区块链技术应用于人工智能领域的可行性,最后提出展望。     

基于区块链物联网的抽样检测平台

当前我国的抽样检测平台信息化智能化程度较低导致抽检工作效率低下, 且中心化平台导致了数据可篡改与来源不可信问题. 针对这些问题, 提出了一种面向抽样检测的区块链技术方案, 利用区块链中联盟链多中心化、不可篡改、隐私保护等特点, 结合物联网终端设备对过程的智能感知, 实现了数据安全可信, 过程可追溯可监控的抽样检测平台, 提高了抽样检测的效率与检测结果的可信性, 保障了数据的安全性.     

区块链中Merkle树性能研究

区块链技术具有去中心化、安全可靠和不可篡改等特性,已经得到广大的重视. Merkle树是区块中核心组成部分,占据区块存储空间的96%以上,主要用来解决在区块链交易中的简化支付验证问题,因此选择合适的Merkle树结构会极大影响区块链系统性能.但是,目前缺乏公共的平台对不同区块链系统下的Merkle树性能进行分析和实验验证.本文提出了一整套相关性能评价与分析指标,从存储、验证和构建时间等方面,综合评价比特币、以太坊和超级账本三种主流区块链的Merkle树的性能.本文提出的指标及评价方法不仅为Merkle树的进一步研究提供了定量的数据支持,也为区块链从业者选择Merkle树结构提供了理论依据.     

基于CP-ABE算法的区块链数据访问控制方案

与公有链不同,联盟区块链超级账本Fabric额外集成了成员管理服务机制,能够提供基于通道层面的数据隔离保护。但这种数据隔离保护机制在通道内同步的仍是明文数据,因此存在一定程度的数据泄露风险。另外,基于通道的数据访问控制在一些细粒度隐私保护场景下也不适用。为了解决上述提及的联盟链超级账本中存在的数据隐私安全问题,提出了一种基于CP-ABE算法的区块链数据访问控制方案。结合超级账本中原有的Fabric-CA模块,提出的方案在实现用户级细粒度安全访问控制区块链数据的同时,还能够实现对CP-ABE方案中用户属性密钥的安全分发。对该方案进行的安全分析表明,该方案实现了ABE用户属性私钥安全分发和数据隐私性保护的安全性目标,性能分析部分也说明了所提方案具有良好的可用性。     

VacChain: A Blockchain-Based EMR System to Manage Child Vaccination Records

The digitalization of healthcare-related information service systems has become a trend across the world. However, several crucial services are still provided manually due to a lack of trust in digital solutions. One such service is keeping records of children’s vaccination, which still relies on a paper-based file system in most parts of the world. This approach causes serious data integrity problems. Recently, healthcare has become a potential application area of the blockchain, as it can preserve and protect highly sensitive private medical records while sharing these records in a decentralized manner without losing personal ownership. Therefore, we propose a new digital model to track a child’s vaccination records using blockchain. In particular, this proposed application helps improve the vaccination record-keeping process by ensuring the integrity of the preserved data in a more secure way. In an emerging pandemic situation, our approach can be extended to manage the overall vaccination process effectively.     

Proof-of-Improved-Participation: A New Consensus Protocol for Blockchain Technology

The Internet of Things (IoT) is converting today’s physical world into a complex and sophisticated network of connected devices on an enormous scale. The existing malicious node detection mechanism in traditional approaches lacks in transparency, availability, or traceability of the detection phase. To overcome these concerns, we provide a decentralized technique using blockchain technology. Despite the fact that blockchain technology is applicable to create that type of models, existing harmony set of instructions are susceptible to do violence to such as DoS and Sybil, making blockchain systems unfeasible. Here, a new Proof-of-Improved-Participation (PoIP) harmony instruction was suggested that benefits the participation rules to select honest peers for mining while limiting malicious peers. Under an evaluation the PoIP outperforms the Proof-of-Work (PoW) instructions are demonstrated, Proof of Stake (PoS) instructions in terms of energy consumption, accuracy, and bandwidth. To compare the three consensus protocols with respect to efficiency, we build a lightweight mining model and find that PoIP consensus has greater efficiency than PoW and PoS. PoIP has 25% lower attack risk than existing consensus. As a consequence, our suggested methodology can provide the needed security with minimal attack risk and high accuracy, according to the analysis results. As a result, suggested consensus is more efficient than existing methods in terms of block generation time. Hence we suggest that suggested consensus is very suitable for IoT-based applications especially in healthcare.     

区块链即服务:下一个云服务前沿

区块链的本质是分布式账本.它作为比特币的底层技术日益被熟知,具有去中心化、开放性、自治性、信息不可篡改、匿名性的特点.区块链即服务(blockchain as a service)则是把区块链当作基础设施,并在其上搭建各种满足普通用户需求的应用,向用户提供服务.区块链即服务已成为云计算领域的研究重点.研究了区块链即服务最新的技术发展状况,结合行业研究和企业实践探索,对区块链即服务的架构以及各模块功能进行了概要设计说明,为区块链即服务的发展提供了通用架构模型.另外,分析了结合区块链即服务的云计算相关技术特点,并给出了可能的攻击模型.最后,结合行业区块链即服务的应用,对区块链即服务的技术前景进行了展望.     

基于区块链的铁路电子提单系统

提单是国际物流中的重要单证,应用于铁路运输时将提高货物和资金流转效率.现存的电子提单系统存在安全性低、公信力不足等问题,难以保障各个参与方的权益.本文在满足提单主要功能的基础上,利用区块链去中心化、可溯源、可编程的特性,确定了基于区块链的电子提单系统框架.采用超级账本技术,本文设计并实现了在区块链网络中多机构、多角色参与的电子提单发布、审核、质押等业务逻辑,保证了电子提单安全、高效地流转.经过区块链系统打包的交易数据,凭借共识机制被锚定在链上,实现了交易信息实时共享与查询,有效地解决了物权争议与货物追踪问题.     

物链网综述:区块链在物联网中的应用

物联网设备数量的激增和中心化的管理架构给物联网的发展带来了严峻的挑战，区块链技术的去中心化和不可篡改等特点可以用来解决物联网的上述难题，故此将区块链技术应用到物联网领域成为研究热点。随着区块链技术在物联网应用中的深入研究，出现了一个新的概念："物链网"。本文首先介绍了物联网的行业痛点和区块链相关技术，然后分析了将区块链技术应用到物联网领域的论文和白皮书，把融合文献分为平台架构和应用场景两类后，进行归纳总结，并调研了应用领域的典型公链和商业项目，指出了将区块链技术应用于物联网领域所面临的挑战与机遇，讨论了相应的解决方案，最后展望了"物链网"未来的发展趋势，提出未来研究方向应侧重于数据存储和数据管理方向。     

A Storage Optimization Scheme for Blockchain Transaction Databases

As the typical peer-to-peer distributed networks, blockchain systems require each node to copy a complete transaction database, so as to ensure new transactions can by verified independently. In a blockchain system (e.g., bitcoin system), the node does not rely on any central organization, and every node keeps an entire copy of the transaction database. However, this feature determines that the size of blockchain transaction database is growing rapidly. Therefore, with the continuous system operations, the node memory also needs to be expanded to support the system running. Especially in the big data era, the increasing network traffic will lead to faster transaction growth rate. This paper analyzes blockchain transaction databases and proposes a storage optimization scheme. The proposed scheme divides blockchain transaction database into cold zone and hot zone using expiration recognition method based on Least Recently Used (LRU) algorithm. It can achieve storage optimization by moving unspent transaction outputs outside the in-memory transaction databases. We present the theoretical analysis on the optimization method to validate the effectiveness. Extensive experiments show our proposed method outperforms the current mechanism for the blockchain transaction databases.     

可编辑区块链: 模型、技术与方法

可编辑区块链是区块链领域新兴而颇有争议的热点课题, 致力于在保障区块链安全可信等良好性质的前提下实现链上数据的可控编辑操作. 本文系统性地梳理和研究了可编辑区块链技术在信息安全和监管等领域面临的现实需求, 提出了可编辑区块链的工作框架, 并从数据修改、删除、插入、过滤和隐藏五个环节详细阐述了可编辑区块链的技术与方法, 最后讨论了该领域亟需解决的若干关键问题.     

支撑财政转移支付的区块链技术方案研究

为提升财政转移支付业务办理效率,提高数据安全可信程度,增强监督审查质效,充分利用区块链技术去中心化、防篡改、可追溯、公开透明的特点,提出了一种基于Hyperledger Fabric平台的转移支付系统.由中央、省、市、县四级行政区划构成区块链网络节点,按照各级财政转移支付业务特点划分出业务通道,解决了数据监督与数据隐私...     

一种扩展的使用控制模型及其实施模型*

指出了原有UCON模型缺乏对特定使用会话中资源使用之后的行为处理能力、过度简化了使用会话的概念以及缺乏一种综合考虑其决策连续性和属性可变性特征的实施机制这几个方面的问题。针对上述问题,给出了一个完整的职责模型,扩展了原有的UCON,并提出了一种通用的使用控制实施模型。     

平行区块链:概念、方法与内涵解析

本文提出了平行区块链的概念框架、基础理论和研究方法体系,并探讨了平行区块链的内涵.平行区块链技术是平行智能理论方法与区块链技术的有机结合,致力于通过实际区块链系统与人工区块链系统的平行互动与协同演化,为目前的区块链技术增加计算实验与平行决策功能,实现描述、预测、引导相结合的区块链系统管理与决策.平行区块链这一新型研究范式可望为下一步区块链研究和未来产业应用提供有益的启发与借鉴.     

Cooperative Detection Method for DDoS Attacks Based on Blockchain

Distributed Denial of Service (DDoS) attacks is always one of the major problems for service providers. Using blockchain to detect DDoS attacks is one of the current popular methods. However, the problems of high time overhead and cost exist in the most of the blockchain methods for detecting DDoS attacks. This paper proposes a blockchain-based collaborative detection method for DDoS attacks. First, the trained DDoS attack detection model is encrypted by the Intel Software Guard Extensions (SGX), which provides high security for uploading the DDoS attack detection model to the blockchain. Secondly, the service provider uploads the encrypted model to Inter Planetary File System (IPFS) and then a corresponding Content-ID (CID) is generated by IPFS which greatly saves the cost of uploading encrypted models to the blockchain. In addition, due to the small amount of model data, the time cost of uploading the DDoS attack detection model is greatly reduced. Finally, through the blockchain and smart contracts, the CID is distributed to other service providers, who can use the CID to download the corresponding DDoS attack detection model from IPFS. Blockchain provides a decentralized, trusted and tamper-proof environment for service providers. Besides, smart contracts and IPFS greatly improve the distribution efficiency of the model, while the distribution of CID greatly improves the efficiency of the transmission on the blockchain. In this way, the purpose of collaborative detection can be achieved, and the time cost of transmission on blockchain and IPFS can be considerably saved. We designed a blockchain-based DDoS attack collaborative detection framework to improve the data transmission efficiency on the blockchain, and use IPFS to greatly reduce the cost of the distribution model. In the experiment, compared with most blockchain-based method for DDoS attack detection, the proposed model using blockchain distribution shows the advantages of low cost and latency. The remote authentication mechanism of Intel SGX provides high security and integrity, and ensures the availability of distributed models.     

面向纯文本信息隐藏的区块链隐蔽通信模型

纯文本信息隐藏容易遭受删除、更改等主动攻击,使嵌入的秘密信息遭到破坏.区块链因具有不可篡改、不可伪造、匿名性、节点信息同步等特点,成为构建隐蔽信道的天然平台,并确保秘密信息不被破坏.文中提出了一种面向纯文本信息隐藏的区块链隐蔽通信模型.首先,根据偏序关系确定嵌入秘密信息的位置,发送方使用空格法将秘密信息嵌入到纯文本内容...     

DRRS-BC: Decentralized Routing Registration System Based on Blockchain

The border gateway protocol (BGP) has become the indispensible infrastructure of the Internet as a typical inter-domain routing protocol. However, it is vulnerable to misconfigurations and malicious attacks since BGP does not provide enough authentication mechanism to the route advertisement. As a result, it has brought about many security incidents with huge economic losses. Exiting solutions to the routing security problem such as S-BGP, So-BGP, Ps-BGP, and RPKI, are based on the Public Key Infrastructure and face a high security risk from the centralized structure. In this paper, we propose the decentralized blockchain-based route registration framework-decentralized route registration system based on blockchain (DRRS-BC). In DRRS-BC, we produce a global transaction ledge by the information of address prefixes and autonomous system numbers between multiple organizations and ASs, which is maintained by all blockchain nodes and further used for authentication. By applying blockchain, DRRS-BC perfectly solves the problems of identity authentication, behavior authentication as well as the promotion and deployment problem rather than depending on the authentication center. Moreover, it resists to prefix and subprefix hijacking attacks and meets the performance and security requirements of route registration.      

区块链在车载自组网中的应用研究及展望

车载自组织网络(简称车载网)是一种由车辆节点和路侧节点(基础设施)构成的自组织网络,是智能交通(Intelligent Transport System,ITS)领域的核心技术之一。区块链的分布式数据存储、点对点传输、共识机制、加密算法等技术可保证车载网中的安全性、可靠性,但是区块链的强一致性和链式结构特点无法满足车载网的两个主要特性,即车辆节点快速移动性和网络不稳定性。文中重点研究区块链在车辆节点移动性和网络不稳定性条件下的节点、存储、跨链、共识等技术特性,分析存在的问题并提出解决方法,最后展望区块链在车载网中的新应用及研究方向,为今后的研究提供参考。     

Blockchain Consistency Check Protocol for Improved Reliability

Blockchain is a technology that provides security features that can be used for more than just cryptocurrencies. Blockchain achieves security by saving the information of one block in the next block. Changing the information of one block will require changes to all the next block in order for that change to take effect. Which makes it unfeasible for such an attack to happen. However, the structure of how blockchain works makes the last block always vulnerable for attacks, given that its information is not saved yet in any block. This allows malicious node to change the information of the last block and generate a new block and broadcast it to the network. Given that the nodes always follow the longer chain wins rule, the malicious node will win given that it has the longest chain in the network. This paper suggests a solution to this issue by making the nodes send consistency check messages before broadcasting a block. If the nodes manage to successfully verify that the node that generated a new block hasn’t tampered with the blockchain than that block will be broadcasted. The results of the simulation show suggested protocol provided better security compared to the regular blockchain.     

Blockchain: Secured Solution for Signature Transfer in Distributed Intrusion Detection System

Exchange of data in networks necessitates provision of security and confidentiality. Most networks compromised by intruders are those where the exchange of data is at high risk. The main objective of this paper is to present a solution for secure exchange of attack signatures between the nodes of a distributed network. Malicious activities are monitored and detected by the Intrusion Detection System (IDS) that operates with nodes connected to a distributed network. The IDS operates in two phases, where the first phase consists of detection of anomaly attacks using an ensemble of classifiers such as Random forest, Convolutional neural network, and XGBoost along with genetic algorithm to improve the performance of IDS. The novel attacks detected in this phase are converted into signatures and exchanged further through the network using the blockchain framework in the second phase. This phase uses the cryptosystem as part of the blockchain to store data and secure it at a higher level. The blockchain is implemented using the Hyperledger Fabric v1.0 and v2.0, to create a prototype for secure signature transfer. It exchanges signatures in a much more secured manner using the blockchain architecture when implemented with version 2.0 of Hyperledger Fabric. The performance of the proposed blockchain system is evaluated on UNSW NB15 dataset. Blockchain performance has been evaluated in terms of execution time, average latency, throughput and transaction processing time. Experimental evidence of the proposed IDS system demonstrates improved performance with accuracy, detection rate and false alarm rate (FAR) as key parameters used. Accuracy and detection rate increase by 2% and 3% respectively whereas FAR reduces by 1.7%.