【作者】 孙道清；

【导师】 曹奇英；

【作者基本信息】 东华大学 ， 控制理论与控制工程， 2008， 博士

【摘要】 普适计算是信息空间与物理空间的融合,在这个融合的空间中人们可以随时随地和透明地获得环境所提供给我们的服务。在这一服务实现的过程中,安全问题逐步进入到人们的视野。尤其是将普适计算大规模应用到我们的现实生活中以提高我们的生活质量的背景下,安全问题显得更为重要。认证是安全服务的第一关。传统的认证方式在普适计算环境下面临着新的挑战,包括对在线可信第三方的弱化或否定,对认证技术复杂度的制约,认证的匿名性、多等级、多层次、直接双向性方面的需求等。这就要求必须要对普适计算环境下的认证技术进行研究。认证不提供关于其自身的任何安全保证。更恰当地说,安全保证依赖于对被认证实体的信任,如使用口令或者生物测定学等方式能正确授予用户访问机密资源或享受机密服务的权限,但是仅在用户可信的情况下,该资源或服务才是安全的。因此必须要将认证和信任结合起来才能增强普适计算环境下的服务安全性。传统的信任研究在普适计算环境下同样面临着新的挑战,这些挑战包括信任的非二元性挑战,信任的非静态性挑战,信任多重性挑战(如身份认证必须要和行为信任相结合、信任与所提供或享受的服务类别之间的相关性、信任的计算必须要与风险评估与决策等相关联起来)等。因此,研究普适计算环境下的信任计算机制将是非常必要的。为了对普适计算环境中的实体提供实时和合适的服务,环境、服务提供者和服务享受者之间在服务实现的过程中,安全方面又面临着特殊的考验。这些考验包括服务的安全委托,环境差异性的解决,服务的分类和分等级处理需求及其解决方案,被服务的对象或提供服务的对象的身份匿名性保障等。这些都是在本论文中要被着重研究和解决的问题。本文的主要研究工作和创新成果如下:将SPKI引入到普适计算环境中来,解决了普适计算环境下的认证和服务授权等方面的安全问题。提出了安全认证协议——基于属性的普适计算环境下的身份认证协议,全面应对了认证研究在普适计算环境下所面临的挑战。给出了安全认证协议在普适计算环境下的一个模拟的应用示例——基于信任度约束的身份来进行安全认证的模型UCIAMdess,以拓展普适计算环境下认证研究的理论和应用价值。选择D-S理论作为研究的技术基础,并对该理论进行了完善。提出了普适计算环境下的信任计算模型,并给出了该模型的应用场景以及在这些场景下的仿真实验结果与分析。从而解决了普适计算环境下的信任非静态性问题、信任的多重性问题和信任的推荐问题等,为全方位、深层次的普适计算安全服务问题的研究打下了坚实的基础和保障。将D-S理论和SPKI理论有机地结合起来,提出了eSPKI理论,包括eSPKI信任证书六元组的约简规则与约简算法等。然后在这些的基础上提出了服务安全委托协议UCSSRAP和安全服务模型UCSMss。前者通过对服务证书的委托授权和证书链的管理实现了服务的安全委托,后者通过对服务的授权、实施、证书校验、服务控制等措施实现了普适计算环境下安全服务的目的。最后给出了利用服务安全委托协议和安全服务模型来解决普适计算环境下服务的安全性问题的几个应用研究实例。包括用于解决大范围(全球环境)的UCSMssp;用于提供集认证、信任、决策和风险评估于一体的UCSMdess;为了提供合适的和实时的服务而作的UCCSSM研究成果和为了保护服务提供过程中用户的敏感信息而作的UCAIPM等研究内容。这些成果为普适计算环境下的安全服务研究打下了坚实的理论和应用基础。更多还原

【Abstract】 Ubiquitous computing is the integration of the physical space and the information space where the users can obtain digital services expediently and transparently.During this integration processes,the security problems are coming into our view,which become more and more significant when the quality of life is expected to improve by applying the ubiquitous computing into our real world on a large-scale.The identity authentication is the first pass to the security services.The classical identity authentication mechanisms are confronted with many new challenges while they are used to solve the applications in the ubiquitous computing.The difficult points are the weakening and denial of the online TTP-based test,the complexity of identity authentication processes,the requirements of anonymity identity authentication,multi-level identity authentication,multi-classification identity authentication,direct and bidirectional identity authentication etc while applying these identity authentication mechanisms into ubiquitous computing environments.These let the ubiquitous computing identity authentication be researched.The identity authentication does not ensure the principal itself any security,that is to say,security only depends on the trust to the principal. For example,the user is granted the correct rights to access the secret resource and to enjoy secret service by using password and biometrics,but the resource or the service is security just when the user is credible. Therefore the identity authentication should be combined with trust to improve the security of the implementation processes of the services in ubiquitous computing environments. The researches on classical trust are faced with the new challenges while they are used to solve the applications in the ubiquitous computing. These challenges include the non-duality of trust,the non-static-state of trust, and the multi-hierarchy(The identity must be integrated with the behavior trust,the trust must be connected with the service sorts,and the trust computing must be associated with decision-making etc).Thus,it is necessary to research the ubiquitous computing trust mechanism.In order to provide the suitable and real-time services to the principal under the ubiquitous computing environments,the environments and the services provides and the principals face the special troubles during the implementation of the services,which include the security delegation to the services,the difference between the different environments,the service level and the service classification,the identity hiding to the principal etc.These troubles must be researched and solved in this paper.The main work and contributions of our researches are summarized as follows:To solve the problems of the identity authentication to the principal and the service authorization in the ubiquitous computing environments,the SPKI theory is introduced.The attribute-based ubiquitous computing identity authentication protocol is presented,that answer the identity authentication challenges.Application to this protocol is also presented to show how does the ubiquitous computing security identity authentication work.This application research is named UCIAMdess that is ubiquitous computing identity authentication model based on D-S theory and extended SPKI/SDSI.That develops the theory and application values to the ubiquitous computing identity authentication researches.Secondly,the Dempster-Shafer Theory is introduced into my researches,which has been improved into related trust computing theorem. Ubiquitous computing trust model is presented,the application scenarios and the simulation experiment results to this model are given and analyzed as well.The ubiquitous computing trust compute problems such as the non-static-state of trust,the multi-hierarchy and the trust recommendation are all solved by using these researches.Following is the eSPKI theory by combining the SPKI theory with D-S theory.Ubiquitous computing service security recommendation authorization protocol UCSSRAP and ubiquitous computing service model UCSMss are presented.The former achieved service security recommendation authorization by using service certificate recommendation authorization and certificate chain management.The later achieved the security service by using service authorization and certificate validation and service control.And then,the security application researches are presented based on these theories.These researches are UCSMssp that used to extend application area to whole Internet,UCSMdess that used to integrated the identity authentication and trust computing and design-making and risk evaluation,UCCSSM that used to provide suitable and Real-time service and UCAIPM that used to protect sensitivity information during the service processes.This work is partially supported by the Ministry of Education Technology Research Key Foundation of China under grant(NO.104086).更多还原