面向数字孪生边缘网络的区块链分片及资源自适应优化机制

为了解决数字孪生边缘网络数据共享面临的隐私和安全问题,提出一种基于区块链分片的数字孪生边缘网络数据安全共享机制。考虑动态时变的数字孪生边缘网络和边缘网络孪生模型与物理网络映射误差,建立联合多播簇头选择、本地基站（BS）共识接入选择、频谱和计算共识资源分配的自适应资源优化模型,实现最大化区块链分片交易吞吐量的目标。在数字孪生边缘网络环境下,提出双层近端策略优化（PPO）算法,求解自适应资源优化问题。仿真结果表明,所提算法可以有效改善区块链分片交易吞吐量。同时,在适应映射误差方面优于传统深度强化学习算法。     

基于图神经网络的账户余额模型区块链地址分类方法

为了监管账户余额模型公链上的交易,有必要对该类区块链上的交易进行地址分类研究。基于此,提出了一种基于图神经网络的账户余额模型区块链地址分类方法（简称AJKGS-ABCM）以实现区块链地址的分类,为区块链交易追踪提供有效的支持。该方法将区块链交易数据建模为图结构,以地址为节点,交易为边,提出AJK-Graph SAGE算法学习图的嵌入表示,模型的输入只需要节点及其采样的邻居节点集合。同时,模型引入注意力机制及跳跃知识结合策略,自适应地为不同层的表示分配权重,并在不同层间共享信息,提高了训练速度和泛化能力。最后进行了实验对比,结果表明该模型在准确度、召回率和F1分数上性能优于其他方法。     

基于联盟区块链的高效性能优化中间件研究

区块链已成为现代甚至未来众多应用程序中最具吸引力的技术之一.目前Fabric是实现企业级区块链的开源联盟区块链,其性能的不足一直是区块链的瓶颈,其大规模数据运行的性能并不理想,本论文对区块链进行区块交易解析并设计了一种多链架构,基于HASH取模算法和Merkle Tree从交易到查询研究设计了页面与区块链的一致性验证的...     

基于需求响应的电力交易区块链跨链协调调度算法

传统交易区块链调度算法不能有效解决电力交易模式混乱的问题,导致电力交易协调调度效果较差,提出基于需求响应的电力交易区块链跨链协调调度算法.通过查看区块链跨链方式相关信息,经过任务调度中心自行修改任务,在需求响应下清晰划分电力跨链交易模式.以电力交易模式为基础,计算电力交易的信息熵,并根据不同区块之间耦合约束条件确定电力...     

面向车联网异构节点的区块链高效一致性共识算法研究

车联网异构节点由于其性能差异大、具有移动性等原因会造成区块链共识算法交易吞吐率低、交易时延较大等问题,该文提出面向车联网异构节点的区块链高效一致性共识算法(ECCA)。首先,在ECCA中,考虑由验证节点、一般节点和恶意节点组成的车联网异构节点,提出一种信用等级机制,实现信用等级划分和3类异构节点的划分。其次,提出一种跨区下的节点身份变更机制,及时调整当前区域内的节点身份。最后,提出一种改进的一致性共识算法,满足车联网的时效性需求。仿真结果表明：ECCA算法降低性能较差的一般节点和恶意节点对区块共识效率的影响,提高交易吞吐量,降低平均交易时延和平均节点通信开销。     

基于区块链的长租房可靠交易系统设计与实现

针对当前长租房系统中出现的难以维权、信息不对称等问题,同时改善用户的使用体验,开发一套基于区块链的长租房可靠租赁交易系统。从用户的实际需求与利益出发,系统基于区块链技术的不可篡改性、自治性等特点,依托于共识机制,并通过智能合约进行交易,同时根据现实需求对当前区块链网络结构与共识算法进行优化。能够解决租房过程中“第三方信任”的问题,可以提高平台的用户可信度、改善国内长租房整体环境,响应国家政策、保障民生,推动国内长租房市场健康蓬勃发展。     

基于代理重加密的区块链数据受控共享方案

区块链以分布式共享全局账本的形式存储交易数据，数据共享难以实现隐私保护和可用性之间的平衡，现有的区块链数据共享方案在进行隐私保护的同时可用性较低，有效实现区块链数据访问权限的动态调整是一个挑战性问题.为此，本文提出基于代理重加密的区块链数据受控共享方案.首先，基于SM2构造代理重加密算法，并借此设计区块链数据受控共享方案，利用代理重加密保护交易数据隐私实现数据安全共享.其次，提出用户权限动态调整机制，区块链节点分工代理并对重加密密钥参数分割管理，实现用户访问权限确定性更新，交易数据的可见性得到动态调整.最后，安全性和性能分析表明，本方案可以在保护交易隐私的同时，实现区块链数据动态共享，并且在计算开销方面具有优势，更好地适用于区块链数据受控共享.     

联盟链SChain架构设计方法

区块链技术作为数字时代的新型基础设施，具有广阔的应用前景。目前开源区块链系统众多，但是彼此体系不统、数据不通，对于全国统一数字信任基础设施的构建造成了一定阻碍。通过对以太坊2.0、超级账本、Fisco Bcos等开源区块链服务平台的研究，从网络架构、核心流程、特点分析等角度进行了分析比较，提出了一种新型联盟链架构设计方法（SChain），明确了系统架构、共识选主、交易共识、扩展设计，并进行了安全性分析和性能测试。     

一种基于指纹存证协助的智能合约模型的设计

区块链技术作为分布式记账技术,为电网中多方交易提供了信任平台。由于数字信息易被复制和篡改,如何安全、可靠存储存证成为亟待解决的问题。为此,提出基于指纹存证协助的智能合约模型。将指纹存证和区块链相结合,充分发挥指纹存证的存证效率高、存储量小的特点。区块链端用于记录电网资产关键数据及其信息变更的HASH值,保证存证信息的真实可信。同时,采用环签名技术,进一步提高了存证信息的安全性。采用Solidate语言设计区块链智能合约模型,提升系统效率。经分析与实验表明,该模型提高了存证信息的安全性和系统吞吐量。     

基于信用等级划分的医疗数据安全共识算法

在基于区块链的医疗数据共享系统中为防御恶意节点攻击并且提高共识效率,该文提出基于信用等级划分的医疗数据安全共识算法(SCA_MD)。首先,在SCA_MD中,考虑由数据节点、共识节点和监管节点组成的医疗区块共识模型,提出相应的节点身份验证机制,实现快速验证。其次,提出基于海洋掠食者的自我优化信用等级划分算法(SCRD),以限制恶意节点共识权力。最后改进代表节点选举机制和共识机制,提高共识的效率。实验结果表明：不管恶意节点数量如何变化,SCA_MD都能提高交易吞吐量,降低平均交易时延和平均节点通信开销。     

Information transmission mechanism of Blockchain technology based on named-data networking

Recent researches on blockchain have been greatly concerned by academia and industry,while the communication based on TCP/IP protocol was not enough for broadcasting a large volume of data in blockchain technology.Therefore,a novel node model supporting push service for blockchain technology and a special procedure reading-writing the table of the node model were designed based on the named-data networking,which was a distributed network architecture supporting data transmission naturally.And then the information transmission architecture of blockchain technology via named-data networking was proposed.With the aggregation of the requests and data caching,this architecture could reduce the traffic redundancy and accelerate the communication speed.Meanwhile,a use case of bitcoin based on the proposed architecture was given,in order to better understand the architecture.A numerical simulation was used to verify the performance advantages of the proposed scheme.In addition,some related future research directions were presented.     

Research on sybil attack in defense blockchain based on improved PBFT algorithm

Aiming at the problem that sybil attack has great harm to block chain technology,a method to improve the PBFT algorithm in the alliance chain to defend against sybil attacks was proposed.Firstly,using the idea of consensus algorithm based on proof of rights and interests,a reputation model was established,the reputation value of each node accorded to the behavior of each node in the consensus process was calculated,and different discourse rights accorded to the size of the reputation value was given.Then pre-commit phase was added to the PBFT algorithm to reduce the number of communication between nodes.The solution through formal analysis and reasoning and security testing shows that the improved PBFT algorithm can not only effectively defend against sybil attacks in the blockchain,but also make the performance of the blockchain system in terms of TPS and block generation delay.     

IGBT老化状态下基于BAS-SVM模型的结温预测方法

为进一步研究IGBT老化对其结温的影响,提出了一种新型的结温预测方法。通过功率循环加速老化实验,模拟模块实际运行老化状态,获取了不同老化程度下的饱和压降、集电极电流和结温数据,并进行分析。采用数据驱动的方法,建立了基于天牛须搜索算法优化支持向量机(BAS-SVM)的结温预测模型。结果表明,与粒子群算法-支持向量机(PSO-SVM)模型和天牛须搜索-BP神经网络(BAS-BP)模型相比,BAS-SVM模型更能有效缩短训练时间,收敛速度更快,且对IGBT结温的预测精度更高,是一种更有效的预测模型。     

Endogenous trusted network architecture for intelligent sharing

To address the needs of intelligent sharing of network resources,blockchain and artificial intelligence were integrated with the network,and an endogenous trusted resource intelligent sharing network architecture was proposed to make network asset sharing have endogenous trust.Based on distributed alliance blockchain,an integration mechanism of on-chain identification and off-chain resource was proposed to achieve credible management of network resources.Security and trusted sharing protocols for network data was designed to synchronize data consensus within the network.Based on smart contract,network resource scheduling and service composition methods were presented to achieve trusted service sharing.Finally,the proposed architecture was applied to decentralized scenarios such as domain name resolution,cross domain authentication,and virtual network operation.The proposed architecture realizes the integration of blockchain and network and supports the endogenous trusted sharing of network assets.     

基于数据挖掘技术的移动通信话务预测模型探析

本文探讨引入数据挖掘技术和算法,通过3种高精度话务预测模型对某市话务数据建模和预测验证,探析3种模型的实际误差和适用场景,并提出基于数据挖掘技术的移动通信智能话务预测管理平台架构设想,具有较高的推广和应用价值。     

Design and implementation of labor arbitration system based on blockchain

Data island and information opacity are two major problems in collaborative administration. Blockchain has the potential to provide a trustable and transparent environment encouraging data sharing among administration members. However, the blockchain only stores Hash values and transactions in blocks which makes it unable to store big data and trace their changes. In this paper, a labor arbitration scheme based on blockchain was proposed to share labor arbitration data. In the system, a collaborative administration scheme that provides a big data storage model combined blockchain and interplanetary file system ( IPFS) is designed. It can store big data and share these data among different parties. Moreover, a file version control mechanism based on blockchain is designed to manage the data changes in IPFS network. It creates a tracing chain that consists of many IPFS objects to track changes of stored data. The relationship of previous and current IPFS objects recorded by blockchain can describe the changes of administration data and trace the data operations. The proposed platform is used in Rizhao City in China, and the experiment result shows collaborative administration scheme achieves traceability with high throughput and is more efficient than traditional hypertext transfer protocol ( HTTP) way to share data.     

面向TPS架构的混合电路测试系统设计

面向测试程序集（TPS）软件架构是通用自动测试系统的发展方向,而建立统一的测试系统模型是测试系统中资源管理与配置的关键。提出了一种基于TPS的自动测试系统建模方案及实现机制,利用关系型数据库建立包括仪器仪表资源自动配置、被测件管理、测试底版通信控制的自动测试系统模型。基于VC6.0平台,在测试主程序与仪器仪表控制、与测试底版之间建立引擎,实现资源的自动选择和配置,解决了测试程序对仪器仪表的依赖问题及测试底版的通用性问题。该方案已经成功应用于某出口三型雷达综合电路集成测试系统中。     

区块链的安全风险评估模型

随着区块链技术在社会经济领域的应用不断扩大,区块链的安全问题受到越来越多的关注.本文提出了一种新的区块链安全风险评估方法,分别从技术架构和算力两方面量化区块链的安全风险.我们首先根据区块链技术体系架构建立了区块链可信计算基(Blockchain Trusted Computing Base,BTCB),进而设计了一种结...     

Research on a new network covert channel model in blockchain environment

Blockchain is a decentralized architecture emerging with cryptocurrencies,which is credible and robust.A network covert channel model in blockchain environment was proposed for the first time,which was anti-interference,anti-tamper modification,multi-line communication,receiver anonymity and line independence.The shortcomings of network covert channel in existing network environment could be tackled by the new type of network covert channel,such as characteristic defect.etc.Firstly,A network covert channel model in blockchain environment was presented by formal method,its anti-interference and anti-tamper modification was proved.Then,a blockchain network covert channel scenario using service operation interval time was presented.Finally,the undetectability,robustness and rate of the blockchain network covert channel evaluation vectors was proposed.A theoretical foundation was laid for the practicality of the new type of network covert channel in blockchain.     

基于区块链的物联网技术应用

随着区块链技术的不断发展,其应用变得越来越普及。文章主要针对区块链的数据结构及整体架构进行分析,并审视了区块链为物联网带来的挑战;最后从物联网数据交易系统方面、电网管理方面、车联网方面以及防伪安全管理方面,细化阐述了基于区块链的物联网技术应用,以期为基于区块链的物联网技术发展提供可靠支持。