基于UCON改进模型在云环境虚拟访问控制中的应用研究

传统访问控制方法授权都是在访问前进行的，无法处理访问过程中的新授权需求，不适于云环境虚拟网络。为此，将UCON改进模型应用于云环境虚拟访问控制中。构建原始UCON模型，针对UCON模型的弊端，从文件存储和授权方面对UCON模型进行改进。针对文件存储方面，选用GFS模式对服务器端文件进行存储，通过空间变换形式增强隐私文件的安全性；针对授权方面，将用户信任程度看作授权条件，采用客观与主观相结合的信任衡量策略，依据推荐信任与用户信誉实现信任度计算，只有信任度满足授权条件的用户可得到访问权限，为云计算虚拟访问控制添加一道符合其特点的屏障，实现UCON模型改进。将UCON改进模型应用于云环境虚拟网络，实现访问控制。实验结果表明，所提方法能够有效实现文档访问控制、图像访问控制，存取性能高。

Application of UCON based improved model in virtual access control of cloud environment

The traditional access control method is done before the access, and can not handle the new authorization requirements in the access process. It is not suitable for the cloud environment virtual network. Therefore, the UCON improved model is applied to the virtual access control of the cloud environment. The original UCON model is constructed, and the UCON model is improved from the file storage and authorization aspects in view of the drawbacks of the UCON model. For file storage, use GFS mode to store the file server, enhanced security privacy files through space transformation form; for authorization, the user trust degree as authorized by the objective and subjective conditions, combining trust measure strategy, according to the recommended trust and reputation to achieve the calculation of trust degree, trust only meet the conditions of the authorized user can get access to the virtual access control to add a line with the characteristics of the barrier for cloud computing, to achieve improved UCON model. The UCON improved model is applied to the virtual network of cloud environment, and access control is realized. The experimental results show that the proposed method can effectively implement the document access control, image access control and high access performance.