面向拟态云的异构执行体安全调度算法

随着云服务的应用范围越来越广,基于未知漏洞或后门的攻击成为制约云技术发展的主要安全威胁之一。基于拟态防御建立的拟态云服务通过降低漏洞的持续性暴露概率来保障安全性,当前已有研究提出的拟态调度算法缺乏对执行体自身安全性的考虑,并且无法兼顾动态性和异构性。针对此问题文章通过引入执行池的异构度和安全度定义,提出一种基于异构度和安全度的优先级调度算法,并引入结合时间片的动态调度策略。实验结果表明,文章所提算法具有较好的动态性,能够获得较优的调度效果,实现了动态性、异构性和安全性之间的平衡,并且时间复杂度较低。     

拟态通用运行环境的资源管理与调度技术

为达到拟态通用运行环境(MCOE)对已/未知后门和漏洞主动防御、安全威胁攻击及时阻断和数据完整性有效保障等拟态防御目标,提出拟态资源调度准则,基于该准则从拟态资源管理与MCOE框架的交互设计、拟态资源管理与调度等方面论述拟态资源管理服务与调度算法的设计与实现,构造拟态运行节点软硬件资源异构特征分类器及基于三级异构度分类的节点N元组和N异构执行体元组,实现N异构执行体、服务器运行节点资源及其资源对象的随机性、动态性和异构性最大化与资源调度负载均衡,并通过拟态管理服务实例验证了云容器集群上拟态资源管理调度算法的正确性与有效性。     

云环境下面向拟态防御的反馈控制方法

云环境下的虚拟化技术,给用户带来了一些数据和隐私安全问题。针对云环境中虚拟机单一性、同质性和静态性等问题,文章提出一种云环境下面向拟态防御的反馈控制方法。该方法以云中虚拟机为基础,利用拟态防御技术对虚拟机进行拟态化封装,通过反馈控制架构对其实现闭环负反馈控制,并基于异构虚拟机动态轮换改变执行环境,保证虚拟机系统环境的随机性。实验表明该设计实现了对用户服务的错误容忍、可疑虚拟机检测和动态轮换,增加攻击者利用漏洞攻击的难度。     

面向拟态构造Web服务器的执行体调度算法

调度是拟态构造Web服务器的重要机制,现有的调度算法多数缺乏对拟态构造Web服务器异构性和Web服务质量的考虑,不能解决调度机制带来的安全性和Web服务质量不稳定的问题。为此,提出基于最大异构性和Web服务质量的随机种子调度算法,通过计算拟态构造Web服务器所有阈值,随机选出种子执行体,根据最大异构性和Web服务质量确定调度方案。仿真结果表明,与随机调度算法相比,该算法具有较优的调度效果,在安全性、Web服务质量和动态性之间达到了较好的平衡。     

拟态构造的Web服务器异构性量化方法

拟态构造的Web服务器是一种基于拟态防御原理的新型Web安全防御系统,其利用异构性、动态性、冗余性等特性阻断或扰乱网络攻击,以实现系统安全风险可控.在分析拟态防御技术原理的基础上,论证异构性如何提高拟态构造的Web服务器的安全性,并指出对异构性进行量化的重要性.在借鉴生物多样性的量化方法基础上,将拟态构造的Web服务器的异构性定义为其执行体集的复杂性与差异性,提出了一种适用于量化异构性的量化方法,通过该方法分析了影响拟态构造的Web服务器异构性的因素.在理论上为拟态防御量化评估提供了一种新方法,工程实践上为选择冗余度、构件和执行体提供了指导.实验结果表明,该方法比香浓维纳指数和辛普森指数更适合于量化拟态构造的Web服务器的异构性.     

面向云网融合SaaS安全的虚拟网络功能映射方法

在云网融合背景下,承载软件即服务（SaaS）业务功能的云基础设施可能横跨多个数据中心和归属网络,难以保证云资源安全可控。为缩短SaaS业务服务的处理时延,设计基于冗余执行和交叉检验的SaaS组合服务模式,并对容器、Hypervisor和云基础设施的安全威胁进行建模,建立拟态化虚拟网络功能映射模型和安全性优化机制。在此基础上,提出基于近端策略优化的PJM算法。实验结果表明,与CCMF、JEGA和QVNE算法相比,PJM算法在满足安全性约束的条件下,能够降低约12.2%业务端到端时延。     

基于云平台的防御性软件测试服务系统北大核心CSCD

云计算由于具备强大的资源处理能力与高效的计算能力而在当今快速发展,且云计算因可以为用户提供廉价可定制的服务而受到人们的青睐。伴随着云计算技术的进步,云平台承载了越来越多繁杂的应用服务。软件测试作为一种常见而普遍的应用服务,其规模与复杂度近年来不断增长。云平台相比传统的测试模式更能满足软件测试的需求。文章将云平台的软件测试系统分为测试任务的上传、管理、资源分配、执行以及测试任务数据库5个模块,并探讨与测试任务特性相适应的调度原则以高效完成测试任务。文章还探讨了面向云测试平台的安全防护模型,从需求与技术两方面分析了该模型对云测试平台的安全保障。     

VMware继续快速扩展其混合云平台

正VMware公司继续快速扩展其VMware vCloud Air混合云平台,首次推出了全新的混合云服务功能以及全新系列的第三方移动应用服务,上述服务旨在让企业与应用开发者更好地支持现代、移动业务的需求。VMware混合云服务业务部执行副总裁兼总经理Bill Fathers表示:"该业务在今日被认作是现代化、移动性的应用,用于推     

一种基于执行体异构度的拟态裁决优化方法

网络空间拟态防御技术通过构建动态异构冗余的系统架构来提高系统的安全性能,而裁决器的表决机制是防御链中的关键步骤,直接影响拟态系统的安全性和效率。针对拟态表决环节的任务特性,对一致表决算法进行改进,设计基于执行体异构度的拟态裁决优化方法。结合拟态防御系统的异构特性,在选择执行体表决输出时引入执行体间的异构度作为决策因素,同时综合考虑执行体数目和历史记录信息,使表决算法更适用于拟态架构面临的威胁场景。实验结果表明,与一致表决算法相比,该算法能够显著提高拟态系统的安全性能,有效规避共模逃逸的风险。     

面向云制造的服务组合执行引擎框架研究

云制造模式下,制造资源被封装成制造服务,通常以服务组合的方式满足用户复 杂的制造需求。针对云制造服务组合执行过程中高效性、准确性和动态性等要求,提出了面向 云制造的服务组合执行引擎框架,并详细阐述了引擎运行机制。首先,通过解析云制造服务组 合描述文件,构造服务组合节点和服务组合依赖边,建立服务组合节点参数关联关系,归纳推 倒出相应的执行规则。然后,基于执行状态变更的服务组合执行算法实现了制造服务组合的动 态执行。最后,给出了面向电梯产业联盟的云制造服务组合执行引擎实例,验证了框架的可行 性和有效性。     

A security evaluation framework for cloud security auditing

Cloud computing is clearly one of today’s most enticing technologies due to its scalable, flexible, and cost-efficient access to infrastructure and application services. Despite these benefits, cloud service users (CSUs) have serious concerns about the data security and privacy. Currently, there are several cloud service providers (CSPs) offering a wide range of services to their customers with varying levels of security strengths. Due to the vast diversity in the available cloud services, from the customer’s perspective, it has become difficult to decide which CSP they should use and what should be the selection criteria. Presently, there is no framework that can allow CSUs to evaluate CSPs based on their ability to meet the customer’s security requirements. We propose a framework and a mechanism that evaluate the security strength of CSPs based on the customer’s security preferences. We have shown the applicability of our security evaluation framework using a case study.     

CyberGuarder: A virtualization security assurance architecture for green cloud computing

As the sizes of IT infrastructure continue to grow, cloud computing is a natural extension of virtualisation technologies that enable scalable management of virtual machines over a plethora of physically connected systems. The so-called virtualisation-based cloud computing paradigm offers a practical approach to green IT/clouds, which emphasise the construction and deployment of scalable, energy-efficient network software applications (NetApp) by virtue of improved utilisation of the underlying resources. The latter is typically achieved through increased sharing of hardware and data in a multi-tenant cloud architecture/environment and, as such, accentuates the critical requirement for enhanced security services as an integrated component of the virtual infrastructure management strategy. This paper analyses the key security challenges faced by contemporary green cloud computing environments, and proposes a virtualisation security assurance architecture, CyberGuarder, which is designed to address several key security problems within the ‘green’ cloud computing context. In particular, CyberGuarder provides three different kinds of services; namely, a virtual machine security service, a virtual network security service and a policy based trust management service. Specifically, the proposed virtual machine security service incorporates a number of new techniques which include (1) a VMM-based integrity measurement approach for NetApp trusted loading, (2) a multi-granularity NetApp isolation mechanism to enable OS user isolation, and (3) a dynamic approach to virtual machine and network isolation for multiple NetApp’s based on energy-efficiency and security requirements. Secondly, a virtual network security service has been developed successfully to provide an adaptive virtual security appliance deployment in a NetApp execution environment, whereby traditional security services such as IDS and firewalls can be encapsulated as VM images and deployed over a virtual security network in accordance with the practical configuration of the virtualised infrastructure. Thirdly, a security service providing policy based trust management is proposed to facilitate access control to the resources pool and a trust federation mechanism to support/optimise task privacy and cost requirements across multiple resource pools. Preliminary studies of these services have been carried out on our iVIC platform, with promising results. As part of our ongoing research in large-scale, energy-efficient/green cloud computing, we are currently developing a virtual laboratory for our campus courses using the virtualisation infrastructure of iVIC, which incorporates the important results and experience of CyberGuarder in a practical context.     

基于移动Agent的移动云计算系统构建方法

针对移动云计算面临的一系列问题,如应用程序在网络上迁移问题、远程设备上执行时的网络延迟和非持续连接问题、跨云服务问题以及安全风险和隐私问题,提出了一种基于移动Agent范型的移动云计算架构,其中,在应用程序迁移中引入断点保存思想和事件重播机制,在移动Agent协同过程中使用优化过的合同网协议,利用移动Agent交换密钥进行身份认证。用有色嵌套Petri网描述了此架构的执行流程,并在此基础上设计了移动电子图书销售系统。     

Multi-tenant intrusion detection system for public cloud (MTIDS)

Cloud computing is an innovative paradigm technology that is known for its versatility. It provides many creative services as requested, and it is both cost efficient and reliable. More specifically, cloud computing provides an opportunity for tenants to reduce cost and raise effectiveness by offering an alternative method of service utilization. Although these services are easily provided to tenants on demand with minor infrastructure investment, they are significantly exposed to intrusion attempts since the services are offered under the administration of diverse supervision over the Internet. Moreover, the security mechanisms offered by cloud providers do not take into consideration the variation of tenants’ needs as they provide the same security mechanism for all tenants. So, meeting tenants’ security requirements are still a major challenge for cloud providers. In this paper, we concentrate on the security service offered to cloud tenants and service providers and their infrastructure to restrain intruders. We intend to provide a flexible, on-demand, scalable, and pay-as-you-go multi-tenant intrusion detection system as a service that targets the security of the public cloud. Further, it is designed to deliver appropriate and optimized security taking into consideration the tenants’ needs in terms of security service requirements and budget.     

Contract RBAC in cloud computing

Cloud computing is a fast growing field, which is arguably a new computing paradigm. In cloud computing, computing resources are provided as services over the Internet and users can access resources based on their payments. The issue of access control is an important security scheme in the cloud computing. In this paper, a Contract RBAC model with continuous services for user to access various source services provided by different providers is proposed. The Contract RBAC model extending from the well-known RBAC model in cloud computing is shown. The extending definitions in the model could increase the ability to meet new challenges. The Contract RBAC model can provide continuous services with more flexible management in security to meet the application requirements including Intra-cross cloud service and Inter-cross cloud service. Finally, the performance analyses between the traditional manner and the scheme are given. Therefore, the proposed Contract RBAC model can achieve more efficient management for cloud computing environments.     

云计算数据服务主动安全防御系统探讨

随着云计算数据服务的快速发展和应用,大大地改变了人们的工作、学习和生活模式。云计算数据服务带来极大便利的同时,也给人们带来了潜在的威胁,因此需要构建网络安全主动防御系统,提高网络安全性能。文章详细地分析了云计算数据服务面临的安全威胁,阐述了云计算服务平台主动安全防御系统及采用的技术,提高了云计算数据服务平台的安全性能。     

我国云服务发展现状分析及思考

在目前云端应用蓬勃发展的时期,认清应用服务、云计算平台和结合能效的关系尤为必要。应用服务是基础,云端架构是平台,两者结合的能效高低是才是云端服务成败的关键,指出云计算架构不一定能够解决应用的性能问题,低效无序的扩展云计算平台下的应用服务只能造成电力、网络等社会资源的巨大浪费和重复投资。本文观点是云端应用应该立足应用服务,绿色高效的整合云平台才能构建良好的云端应用生态环境。     

Providing efficient SSO to cloud service access in AAA-based identity federations

The inclusion of cloud services within existing identity federations has gained interest in the last years, as a way to simplify the access to them, reducing the user management costs, and increasing the utilization of the cloud resources. Whereas several federation technologies have been developed along the years for the Web world (e.g. SAML, Oauth, OpenID), non-web application services have been largely forgotten. The ABFAB IETF WG was created to define an architecture and a set of technologies for providing identity federation to non-Web application services, such as the cloud. ABFAB provides a way to use the existing EAP/AAA infrastructure to perform federated access control to any kind of application service, thanks to the definition of a new GSS-API mechanism called GSS-EAP. However, the ABFAB architecture does not define an efficient way of providing SSO. This paper defines a way to include such an SSO support into ABFAB, by introducing the required extensions to make use of the EAP Re-authentication Protocol (ERP), the IETF standard for providing fast re-authentication in EAP. Moreover, to demonstrate the feasibility of the proposed extensions, we have implemented a proof-of-concept based on Moonshot, the open-source implementation of ABFAB, and OpenStack as an example of cloud service. Finally, using this prototype we have completed a performance analysis that compares our proposal with the standard ABFAB operation. This analysis confirms the substantial reduction in terms of computational time and network traffic that can be achieved using ERP for providing efficient SSO to cloud service access in ABFAB-based identity federations.     

云环境面向虚拟域的安全状态一致性保障机制研究

由于云环境虚拟化特性及高动态性（回滚、迁移等操作）给虚拟域带来了时间、空间状态不一致,从而造成了严重的安全威胁。针对该问题,提出了云环境虚拟域安全基础架构、时间安全状态一致性机制、空间安全状态一致性机制,有效地保障了云虚拟域安全状态的一致性,有助于提高公共服务效率和信息安全可控性。