Privacy risk adaptive access control model via evolutionary game

Aiming at the problem that in the private sensitive date centralized and opening information systems,a fine-grained and self-adaptive access control model for privacy preserving is desperately needed,thus the balance between privacy preserving and data access utility should be achieved,a rational multi-player risk-adaptive based access control model for privacy preserving was proposed.Firstly,the privacy risk values of access request and requester were formulized by the private information quantity of the requested dataset,and by using Shannon information.Secondly,a risk-adaptive based access control evolutionary game model was constructed by using evolutionary game under the supposing of bounded rational players.Furthermore,dynamic strategies of participants were analyzed by using replicator dynamics equation,and the method of choosing evolutionary stable strategy was proposed.Simulation and comparison results show that,the proposed model is effective to dynamically and adaptively preserve privacy and more risk adaptive,and dynamic evolutionary access strategies of the bounded rational participants are more suitable for practical scenarios.     

面向关联属性的差分隐私信息熵度量方法

针对差分隐私非交互式多属性关联的合成数据集发布问题,基于信息熵、汉明失真提出了发布数据集隐私度、数据效用、隐私泄露风险的量化方法.首先,利用互信息量分析属性相关度,并以关联依赖图模型表达属性关联.其次,基于图中关键隐私泄露路径构建马尔可夫隐私泄露链,并结合信息熵提出一种关联属性隐私度量模型及方法,可以有效的度量由关联属性引起的隐私泄露量.最后,通过具体实例验证了模型与方法的有效性,并对比分析了该方法的优势.     

面向机器学习的隐私保护关键技术研究综述

随着信息通信技术的发展,机器学习已经成为多个研究领域与垂直行业必不可少的技术工具。然而,机器学习所需数据中往往包含了大量的个人信息,使其隐私保护面临风险与挑战,受到了越来越多的关注。对现有机器学习下隐私保护法规政策与标准化现状进行梳理,对适用于机器学习的隐私保护技术进行详细介绍与分析。隐私保护算法通常会对数据质量、通信开支与模型表现等造成影响,因此对于隐私保护算法的评估应当进行多维度的综合评估。总结了适用于机器学习应用的隐私保护性能评估指标,并指出隐私保护需要考虑对数据质量、通信开支以及模型准确率等之间的影响。     

Research on network analysis method for development ability of big data industry in underdeveloped area

Traditional evaluation methods of industrial development ability were mostly lack of objectivity.An evaluation model was proposed by using a BP neural network based on entropy weight.Evaluation index system of big data industry development ability in underdeveloped areas was established.Taking Guizhou industrial development data as samples,entropy weight method was used to determine expected output and compared with the actual output .The experimental results show that the proposed entropy weight-BP evaluation model can optimize error of using single BP network and improve the accuracy and objectivity of evaluation.     

A Composite Privacy Leakage Indicator

This paper proposes a Subjective Logic based composite privacy leakage metric that both takes into account the amount of information leakage and also that information with high entropy in some cases may be considered encrypted. It is furthermore shown both analytically and experimentally that Min-entropy is considered better than Shannon, Rényi or Max entropy for identifying encrypted content for the composite metric. This is in particular useful for implementing privacy-enhanced Intrusion Detection Systems (IDS), where sampled encrypted traffic can be considered to have low risk of revealing sensitive information. The combined metric can be used in a Policy Enforcement Point that acts as a proxy/anonymiser in order to to reduce the leakage of private or sensitive information from the IDS sensors to an outsourced Managed Security Service provider. Although the composite privacy indicator is IDS specific, the authorisation architecture is general, and may also be useful for anonymising or pseusonymising sensitive information from or to other types of sensors that need to be exposed to the Internet. The solution is based on the eXtensible Access Control Markup Language policy language extended with support for Subjective Logic, in order to provide a method for expressing fine-grained access control policies that are based on uncertain evidences.     

Evaluation and protection of multi-level location privacy based on an information theoretic approach

A privacy metric based on mutual information was proposed to measure the privacy leakage occurred when location data owner trust data users at different levels and need to publish the distorted location data to each user according to her trust level,based on which an location privacy protection mechanism (LPPM)was generated to protect user’s location privacy.In addition,based on mutual information,a metric was proposed to measure the privacy leakage caused by attackers obtaining different levels of distorted location data and then performing inference attack on the original location data more accurately.Another privacy metric was also proposed to quantify the information leakage occurred in the scenario based on mutual information.In particular,the proposed privacy mechanism was designed by modifying Blahut-Arimoto algorithm in rate-distortion theory.Experimental results show the superiority of the proposed LPPM over an existing LPPM in terms of location privacyutility tradeoff in both scenarios,which is more conspicuous when there are highly popular locations.     

关于网络环境下用户信息隐私关注的研究

文章以国内期刊发表的有关网络环境下信息隐私关注的文献为研究对象,从研究现状、概念提出、测量模型、研究方法、影响因素、用户隐私行为等方面对现有文献进行梳理和归纳,然后对网络运营商提出降低用户的隐私关注、提高用户提供隐私信息意愿的相关建议,并对我国未来的研究方向做出展望。     

基于热释电红外传感器的人体动作识别方法

针对目前人体动作识别技术中存在的隐私暴露、技术复杂度高和识别精度低等相关问题,提出了一种基于热释电红外（PIR）传感器的人体动作识别方法。首先,采用一组安置在天花板上经过视场调制的PIR传感器采集人体运动时散发的红外热辐射信号,将传感器输出的电压模拟信号进行滤波放大后通过ZigBee无线模块传送到PC端打包成原始数据集;其次,将原始数据的两路传感器输出数据进行特征融合,对融合后的数据做标准化处理封装为训练集和测试集;然后,基于数据的特征提出一种两层级联的混合深度学习网络模型作为人体动作的分类算法,第一层采用一维卷积神经网络（1DCNN）对数据进行特征提取,第二层采用门控循环单元（GRU）保存历史输入信息防止丢失有效特征;最后,利用训练集来训练该网络模型得出参数最优的分类模型,通过测试集验证模型的正确性。实验结果表明,提出的该动作识别技术模型对基本动作分类的准确率高于98%,与图像动作识别或穿戴式设备动作识别相比,实现了实时、便捷、低成本和高保密性的高精度人体动作识别。     

多方数据共享环境下匿名化数据的安全性量化方法(英文)

This paper aims to find a practical way of quantitatively representing the privacy of network data. A method of quantifying the privacy of network data anonymization based on similarity distance and entropy in the scenario involving multiparty network data sharing with Trusted Third Party (TTP) is proposed. Simulations are then conducted using network data from different sources, and show that the measurement indicators defined in this paper can adequately quantify the privacy of the network. In particular, it can indicate the effect of the auxiliary information of the adversary on privacy.     

Practical evaluation of encrypted traffic classification based on a combined method of entropy estimation and neural networks

Encrypted traffic classification plays a vital role in cybersecurity as network traffic encryption becomes prevalent. First, we briefly introduce three traffic encryption mechanisms: IPsec, SSL/TLS, and SRTP. After evaluating the performances of support vector machine, random forest, naïve Bayes, and logistic regression for traffic classification, we propose the combined approach of entropy estimation and artificial neural networks. First, network traffic is classified as encrypted or plaintext with entropy estimation. Encrypted traffic is then further classified using neural networks. We propose using traffic packet’s sizes, packet's inter‐arrival time, and direction as the neural network's input. Our combined approach was evaluated with the dataset obtained from the Canadian Institute for Cybersecurity. Results show an improved precision (from 1 to 7 percentage points), and some application classification metrics improved nearly by 30 percentage points.     

LTPPM: a location and trajectory privacy protection mechanism in participatory sensing

The ubiquity of mobile devices has facilitated the prevalence of participatory sensing, whereby ordinary citizens use their private mobile devices to collect regional information and to share with participators. However, such applications may endanger the users' privacy by revealing their locations and trajectories information. Most of existing solutions, which hide a user's location information with a coarse region, are under k‐anonymity model. Yet, they may not be applicable in some participatory sensing applications that require precise location information. The goals are seemingly contradictory: to protect a user's location privacy while simultaneously providing precise location information for a high quality of service. In this paper, we propose a method to meet both goals. Through selecting a certain number of a user's partners, it can protect the user's location privacy while providing precise location information. The user's trajectory privacy can be protected by constructing several trajectories that are similar to the user's trajectory in an interval time T. Finally, we utilize a new metric, called slope ratio, to evaluate the partners' selection algorithm that we proposed. Then, we measure the privacy level that the location and trajectory privacy protection mechanism (LTPPM) can achieve. The analysis and simulation results show that LTPPM can protect the user's location and trajectory privacy effectively and also provide a high quality of service in participatory sensing. Copyright © 2012 John Wiley & Sons, Ltd.     

基于相对熵和K-means的形状相似差分隐私轨迹保护机制

为解决绝大多数研究未充分考虑位置对隐私预算的敏感程度以及轨迹形状带来的影响,使发布的轨迹可用性较差的问题,提出了基于相对熵和K-means的形状相似差分隐私轨迹保护机制。首先,根据地理空间的拓扑关系,利用相对熵计算真实位置对隐私预算的敏感程度,设计了位置敏感的隐私级别实时计算算法,并与差分隐私预算结合建立了一个新的隐私模型。其次,通过K-means算法对发布位置进行聚类,得到与真实位置方向最相似的发布位置集合,并引入Fréchet距离衡量发布轨迹与真实轨迹的相似性,提升发布轨迹的可用性。通过对真实数据集的实验表明,所提轨迹保护机制与其他方法相比在轨迹可用性方面有明显的优势。     

Background knowledge based privacy metric model for online social networks

The data of online social network （OSN） is collected currently by the third party for various purposes. One of the problems in such practices is how to measure the privacy breach to assure users. The recent work on OSN privacy is mainly focus on privacy-preserving data publishing. However, the work on privacy metric is not systematic but mainly focus on the traditional datasets. Compared with the traditional datasets, the attribute types in OSN are more diverse and the tuple is relevant to each other. The retweet and comment make the graph character of OSN notably. Furthermore, the open application programming interfaces （APIs） and lower register barrier make OSN open environment, in which the background knowledge is more easily achieved by adversaries. This paper analyzes the background knowledge in OSN and discusses its characteristics in detail. Then a privacy metric model faces OSN background knowledge based on kernel regression is proposed. In particular, this model takes the joint attributes and link knowledge into consideration. The effect of different data distributions is discussed. The real world data set from weibo.com has been adopted. It is demonstrated that the privacy metric algorithm in this article is effective in OSN privacy evaluation. The prediction error is 30% lower than that of the work mentioned above     

OW‐SVM: Ontology and whale optimization‐based support vector machine for privacy‐preserved medical data classification in cloud

Cloud is a multitenant architecture that allows the cloud users to share the resources via servers and is used in various applications, including data classification. Data classification is a widely used data mining technique for big data analysis. It helps the learners to discover hidden data patterns by training massive data collected from the real world. Because this trained model is the private asset of an entity, it should be protected from all other noncollaborative entities. Therefore, it is essential to take effective measures to preserve the confidential data. The objective of this paper is to preserve the privacy of the confidential data in the cloud environment by introducing the medical data classification method. In view of that, this paper presents a method for medical data classification using a novel ontology and whale optimization‐based support vector machine (OW‐SVM) approach. Initially, privacy‐preserved data are developed adopting Kronecker product bat approach, and then, ontology is built for the feature selection process. Ontology and whale optimization‐based support vector machine is then proposed by integrating ontology and whale optimization algorithm into SVM, in which ontology and whale optimization algorithm is used for the feasible selection of kernel parameters. The experiment is done using 3 heart disease datasets, such as Cleveland, Switzerland, and Hungarian. In a comparative analysis, the performance of the OW‐SVM approach is compared with that of K‐nearest neighbor, Naive Bayes, decision tree, SVM, and OW‐SVM, using accuracy, sensitivity, specificity, and fitness, as the evaluation metrics. The OW‐SVM approach could achieve maximum performance with accuracy of 83.21%, the sensitivity of 91.49%, specificity of 73%, and fitness of 81.955, outperforming existing comparative techniques.     

Multi-label text classification model based on semantic embedding

Text classification means to assign a document to one or more classes or categories according to content. Text classification provides convenience for users to obtain data. Because of the polysemy of text data, multi-label classification can handle text data more comprehensively. Multi-label text classification become the key problem in the data mining. To improve the performances of multi-label text classification, semantic analysis is embedded into the classification model to complete label correlation analysis, and the structure, objective function and optimization strategy of this model is designed. Then, the convolution neural network (CNN) model based on semantic embedding is introduced. In the end, Zhihu dataset is used for evaluation. The result shows that this model outperforms the related work in terms of recall and area under curve (AUC) metrics.     

隐私计算研究范畴及发展趋势

随着移动互联网、云计算和大数据技术的广泛应用,电商、搜索、社交网络等服务在提供便利的同时,大数据分析使用户隐私泄露的威胁日益凸显,不同系统隐私保护策略和能力的差异性使隐私的延伸管理更加困难,同一信息的隐私保护需求随时间变化需要多种隐私保护方案的组合协同。目前已有的各类隐私保护方案大多针对单一场景,隐私缺乏定量化的定义,隐私保护的效果、隐私泄露的利益损失以及隐私保护方案融合的复杂性三者之间的关系刻画缺乏系统的计算模型。因此,在分析隐私保护研究现状的基础上,提出隐私计算的概念,对隐私计算的内涵加以界定,从隐私信息的全生命周期讨论隐私计算研究范畴,并从隐私计算模型、隐私保护场景适应的密码理论、隐私控制与抗大数据分析的隐私保护、基于信息隐藏的隐私保护以及支持高并发的隐私保护服务架构等方面展望隐私计算的发展趋势。     

车辆自组网的位置隐私保护技术研究

车辆自组网的位置服务在解决道路安全问题、为驾乘者提供便捷服务的同时,也带来了相应的隐私保护问题。总结了隐私保护内容,重点分析了车辆自组网的假名和签名2类隐私保护技术,其中假名方案分为基于特殊地形、基于安静时段、加密mix-zones和mix-zones通信代理;签名方案分为群签名和环签名。继而针对隐私保护水平的高低,分析了匿名集合、熵度量、数学理论分析和形式化证明几类主要的位置隐私度量方法,对其各自的特点进行了总结比较。     

一种基于差分隐私和时序的推荐系统模型研究

推荐系统的建立依赖用户的个人隐私信息,攻击者可以通过推荐的结果对用户的状态和行为进行预测.目前,虽然有对基于协同过滤近邻隐私保护的研究,但是对基于模型的隐私保护的关注度并不够高.差分隐私理论定义了一个相当严格的防攻击模型,通过添加噪声使数据失真达到隐私保护的目的,而且用户的兴趣存在兴趣漂移问题,对推荐效果造成影响,因此,提出基于差分隐私理论和时序理论构建基于模型的推荐系统.首先,根据差分隐私理论,给用户的评分数据增加小波动的符合Laplace分布的噪声,增大待分解矩阵的安全系数;然后,在随机梯度下降模型的基础上,将时序因子建模为时间权重,提高模型的准确性.实验证明该算法的准确性,并且为增强隐私研究提供了新的思路.     

Research on LBS privacy preservation based on pseudorandom permutation in road network

A method of privacy preservation based on pseudorandom permutation was put forward for the issues of location privacy and query content privacy.Firstly,the distribution information of points of interest (PoI) based on the vertexes in the road network was organized,each single road vertex was taken as the foundational processing object.Based on the pseudorandom permutation,a permutation scheme of the point-of-interest records at the LBS server's end was put forward,a 32-bit random seed was adopted to generate a permuted table in the scheme,and the point-of-interest records were encrypted and permuted according to the table.These processed records were stored in the LBS database.Then a trusted intermediate server,replacing of the user,issued a query request with a record number instead of the query content to the LBS server.The LBS server could not determine which kind of PoI the user was interested in or which road section the user was locating on,and therefore the scheme achieved private information retrieval.Finally,the efficiency in the metrics of query accuracy,communication overhead and processing time was also analyzed.By the performance analysis and extensive experiments,the proposed scheme is proved to be location untraceable and query content uncorrelation.     

面向医疗大数据的风险自适应的访问控制模型

面对医疗大数据,策略制定者难以预测医生的访问需求,进而制定准确的访问控制策略。针对上述问题,提出一种基于风险的访问控制模型,能够适应性地调整医生的访问能力,保护患者隐私。该模型通过分析医生的访问历史,使用信息熵和EM算法量化医生侵犯隐私造成的风险。利用量化的风险,监测和控制对于医疗记录的过度访问以及特殊情况下的访问请求。实验结果表明,该模型是有效的,并且相比于其他模型能更为准确地进行访问控制。