基于PBAC模型和IBE的医疗数据访问控制方案

医疗卫生领域形成的医疗大数据中包含了大量的个人隐私信息,面临着外部攻击和内部泄密的潜在安全隐患。传统的访问控制模型没有考虑用户访问目的在侧重数据隐私的访问控制中的重要作用,现有的对称、非对称加密技术又都存在密钥管理、证书管理复杂的问题。针对这些问题,提出了综合应用PBAC模型和IBE加密技术的访问控制方案,支持针对医疗数据密文的灵活访问控制。通过加入条件目的概念对PBAC模型进行扩展,实现了对目的树的全覆盖;以病患ID、条件访问位和预期目的作为IBE身份公钥进行病患数据加密,只有通过认证并且访问目的符合预期的用户才能获得相应的私钥和加密数据,从而实现对病患信息的访问。实验结果证明,该方案达到了细粒度访问控制和隐私保护的目的,并具有较好的性能。     

面向医疗大数据基于零信任的UCON访问控制模型

医疗大数据的共享在现代医疗技术和服务中发挥着重要作用.针对医疗大数据共享过程中的安全性需求,提出了基于零信任和UCON的医疗大数据访问控制模型ZT-UCON.该模型将零信任思想与支持动态连续访问的UCON模型相结合,利用UCON模型的授权、义务和条件等访问控制策略,构建了面向医疗大数据访问控制决策方案.通过在医疗大数据访问控制的一个典型案例中应用ZT-UCON模型,并对比典型的传统访问控制模型,验证了 ZT-UCON的优势.结果表明:基于零信任的UCON访问控制模型,可以降低医疗大数据共享过程中过度访问的可能性,以满足医疗大数据访问控制的安全性需求.     

智慧医疗中基于属性加密的云存储数据共享

在电子病历系统中,为了实现多用户环境下的数据搜索,该文提出一种属性基可搜索加密方案。该文将密文和安全索引存储在医疗云,当用户请求医疗数据时,利用属性基可搜索加密算法进行数据搜索,实现了细粒度访问控制。同时方案引入了密文验证算法,解决了半诚实且好奇的云服务器模型下搜索结果不正确的问题。利用数据去重技术实现了重复数据的消除,减少占用医疗云的存储空间。方案同时实现了访问策略的隐藏,保证了数据用户的隐私安全。安全性分析表明,所提方案能很好地保护用户的隐私以及数据的安全。性能分析表明,该方案具有较好的性能,更加适用于智慧医疗等多对多应用场景,有效实现了医生和第三方数据用户在不侵犯患者隐私的前提下共享患者电子病历。     

基于XML的电子病历系统访问控制模型

由于基于云的电子病历系统需要为不同的医疗机构提供病历的数据共享,因此面临患者医疗数据被泄露的巨大风险,为此文中提出了一个面向访问控制和数据加密签名的两阶段的电子病历系统访问控制模型。该模型通过执行基于属性的访问控制来实现兼具灵活性和细粒度的访问控制,通过执行病历文档加密和电子签名提高病历文档数据的隐私性和不可否认性。系统原型的实现和安全评估表明,相对于当前多数电子病历系统,该系统模型具有更好的数据安全性。     

基于隐私本体的个性化访问控制模型

在信息收集频繁化、普遍化的今天,由用户制定隐私策略、自主控制个人信息访问的方式,可以最大程度满足用户的隐私保护需求。构建的隐私本体,客观反映了隐私保护领域普遍认可的知识,体现了用户最根本的隐私保护需求。基于隐私本体的个性化访问控制模型采用基于隐私本体的通用策略与个性策略相结合的模式,通过多级链式激活的方式实现用户不同粒度、灵活多变的个性化隐私保护需求。     

物联网移动RFID系统匿名访问控制认证密钥交换协议

针对物联网移动RFID系统标签隐私信息的访问控制以及用户身份隐私保护问题,本文采用身份加密和属性加密相结合的方法,建立了IB-AB-eCK安全模型,设计了基于身份及属性的认证密钥交换协议IB-AB-AKE。基于IB-AB-AKE协议,提出了移动RFID手机与信息服务器之间认证密钥交换协议,实现了在保护移动RFID手机用户身份隐私的同时,根据标签所有者定制的访问控制策略进行标签信息的访问控制认证和会话密钥交换,防止了隐私信息被非法访问。分析表明,IB-AB-AKE协议在IB-AB-eCK模型下是安全的,且在通信次数、通信量及计算量方面具有优势。      

支持临时解密授权的密文策略属性加密方案

属性加密是在云环境下实现细粒度访问控制的有效工具,但同类方案并未较好地解决数据所有者的隐私保护和解密权限临时授权问题。文章将属性代理重加密技术与Nishide等的属性加密方案相结合,提出同时支持访问策略隐藏和解密权限临时授权的密文策略属性加密方案。此外,文章利用新方案解决了医疗云环境下属性访问控制系统的构造问题。安全性分析表明,新的属性加密方案并未破坏底层方案的安全性,而且不会向代理服务器泄露数据所有者的解密私钥。     

扩展了信任与隐私的ABAC模型研究

基于属性的访问控制模型(ABAC)特别适用于大规模分布式网络。然而,由于其访问控制决策依赖于属性的暴露,又没有有效的敏感属性保护机制,使得访问主体的敏感属性存在非法暴露的风险。本文提出了一种扩展了信任与隐私的ABAC模型,它包含了信任与隐私这两个特殊属性,并使访问控制决策敏感于跨组织的协作上下文,以解决ABAC模型本身不含敏感属性保护机制的问题。设计了一种促使管理者在危机管理系统中做出更优决策的图形化原型工具,并验证本文方法的有效性。     

基于UCON的访问控制模型在银行中的应用

随着网络技术在银行业务的深入应用,网络的访问控制安全策略对银行数据安全的影响越来越重要,传统访问控制无法有效解决银行网络体系对访问控制的安全性和灵活性需求,对此文中提出了一个种基于UCON(Usage Control Model)使用控制的访问控制模型,该模型提出了比传统访问控制策略更加严格和灵活的访问策略,增强了访问控制环节的安全。     

基于区块链的医疗数据系统设计

电子医疗记录记录了患者诊断和治疗的敏感隐私信息,由于存在数据泄露或更改的风险,在参与者之间共享医疗记录非常困难。为实现电子医疗信息的维护和共享,文章提出了一种基于以太坊的医疗数据管理系统。该系统通过MeatMask生成挖掘数据所需的量,并在存储任何数据时将其存储在区块链中。产生的量用链上手续费表示。数据随后使用MeatMask转换为以太坊货币,然后区块链网络挖掘数据并将数据存入区块链。当医生需要查看数据时,他们必须输入发给患者注册电子邮件的OTP。医生和患者可以使用该技术在区块链网络中安全快捷地保存和访问医疗数据。     

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.     

基于行为的云计算访问控制安全模型

针对当前流行的云计算技术,分析了其所面临的安全问题。以BLP(Bell-LaPadula)模型和Biba模型为参考,通过基于行为的访问控制技术来动态调节主体的访问范围,实现BLP模型和Biba模型的有机结合,提出了CCACSM(cloud computing access control security model)。该模型不仅能保护云端服务器中数据完整性和保密性,而且使云计算环境具有相当的灵活性和实用性。最后给出了该模型的组成部分、安全公理和实现过程。     

PriMa: a comprehensive approach to privacy protection in social network sites

With social networks (SNs) allowing their users to host large amounts of personal data on their platforms, privacy protection mechanisms are becoming increasingly important. The current privacy protection mechanisms offered by SNs mostly enforce access control policies based on users’ privacy settings. The task of setting privacy preferences may be tedious and confusing for the average user, who has hundreds of connections (e.g., acquaintances, colleagues, friends, etc.) and maintains an extensive profile on his main SN. Hence, users often end up with policies that do not sufficiently protect their personal information, thus facilitating potential privacy breaches and information misuse. In this paper, we propose PriMa (Privacy Manager), a privacy protection mechanism that supports semiautomated generation of access rules for users’ profile information, filling the gap between the privacy management needs of SN users and the existing SNs’ privacy protection mechanisms. PriMa access rules are generated using a multicriteria algorithm, so as to account for an extensive set of criteria to be considered when dealing with access control in SN sites. The resulting rules are simple yet powerful specifications, indicating the adequate level of protection for each user, and are dynamically adapted to the ever-changing requirements of the users’ preferences and SN configuration. We have implemented PriMa on a Drupal platform and as a third-party Facebook application. We have evaluated the performance of the PriMa application with respect to access rule generation.     

Encrypted data sharing with multi-owner based on digital rights management in online social networks简

The online social networks（OSNs） offer attractive means for social interactions and data sharing, as well as raise a number of security and privacy issues. Although current solutions propose to encrypt data before sharing, the access control of encrypted data has become a challenging task. Moreover, multiple owners may enforce different access policy to the same data because of their different privacy concerns. A digital rights management（DRM） scheme is proposed for encrypted data in OSNs. In order to protect users＇ sensitive data, the scheme allows users outsource encrypted data to the OSNs service provider for sharing and customize the access policy of their data based on ciphertext-policy attribute-based encryption. Furthermore, the scheme presents a multiparty access control model based on identity-based broadcast encryption and ciphertext-policy attribute-based proxy re-encryption, which enables multiple owners, such as tagged users who appear in a single data, customize the access policy collaboratively, and also allows the disseminators update the access policy if their attributes satisfy the existing access policy. Security analysis and comparison indicate that the proposed scheme is secure and efficient.     

面向社会网络的个性化隐私策略定义与实施

为了实现社会网络中个性化隐私保护,提出了支持个性化隐私偏好授权模型,采用基于一阶逻辑隐私偏好描述语言,表达用户个性化隐私需求;引入基于主体属性的访问者－角色授权规则和基于客体标签的角色－权限指派规则,解决了动态用户授权和细粒度访问权限指派问题;分析了隐私策略冲突各种情况,实现了基于Prolog逻辑编程的策略一致性自动验证;设计了面向社会网络个性化隐私策略管理和实施中间件,将个性化隐私策略管理有效地集成到对既有资源的访问控制系统中,实验表明策略冲突分析具有良好的执行效率。     

Data access control policy of encrypted deduplication system

To solve the problem that convergent encryption was commonly used in existing encrypted deduplication systems in cloud storage and data owner couldn’t effectively enforce access control on their outsourced data,an encrypted deduplication system was proposed to support access control functions such as identity authentication,authorization deduplication and the update of access control policy.The outsourced data was only deduplicated with the authorized users,and the unauthorized users couldn’t obtain any data information.CP-ABE and the partition of the ElGamal private key were used to update the access control policy of data.Self-control objects was used to encapsulate user’s data and its access policy,providing authentication for data visitors and ensuring the access control policies enforced effectively.Security analysis and simulation results demonstrate that the proposed system enables data access control and executes efficiently.     

Multi-authority attribute-based encryption scheme with policy dynamic updating

Attribute-based encryption (ABE) is a new cryptographic technique which guarantees fine-grained access control of outsourced encrypted data in the cloud environment.However,a key limitation remains,namely policy updating.Thus,a multi-authority attribute-based encryption scheme with policy dynamic updating was proposed.In the scheme,an anonymous key issuing protocol was introduced to protect users’ privacy and resist collusion attack of attribute authority.The scheme with dynamic policy updating technique was secure against chosen plaintext attack under the standard model and can support any types of policy updating.Compared to the existing related schemes,the size of ciphertext and users’ secret key is reduced and can significantly reduce the computation and communication costs of updating ciphertext.It is more effective in the practical application.     

基于属性加密的云存储方案研究

云存储中往往采用属性加密方案来实现细粒度的访问控制,为了进一步保护访问控制策略中的敏感信息,并解决授权中心单独为用户生成密钥而产生的密钥托管问题。该文对访问控制策略中的属性进行重新映射,以实现其隐私性。另外在密钥生成算法中设计一个双方计算协议,由用户产生密钥的部分组件,与授权中心共同生成密钥以解决密钥托管问题。最后在标准模型下对方案进行了安全证明,并进行了性能分析与实验验证,实验结果表明,与已有相关方案相比,虽然为了实现访问控制策略隐藏并且解决密钥托管问题增加了额外的计算负载, 但是由于该文将大部分解密工作授权给云存储中心来执行,因此数据访问者的计算负载较小。