一种基于信任的Web Services动态访问控制模型

服务请求者身份的不可知性及其行为的动态不确定性,给Web Services的安全带来了严峻的挑战.在研究和分析现有信任模型不足的基础上,提出一种基于信任的Web Services动态访问控制模型（DWTBAC）.新模型引入时间权重、上下文和推荐强度等客观因素,改进信任值的计算方法,根据信任值-信任等级-权限强度的三元映射关系进行授权管理,实现部分授权.为了抵制恶意行为,提出一种基于服务质量惩罚机制的直接交互经验值更新算法.仿真结果表明,新的访问控制方式,很好地实现了实体信任值随其行为而改变的动态特性,能有效地遏制恶意用户的不良行为,满足Web Services访问控制的安全性和动态性需求.

A Trust-based Dynamic Access Control Model for Web Services

The security of Web services faces a tough challenge for the unpredictability of the web services requester and the dynamic uncertainty of the behavior.Based on the analysis of the shortcoming in current access control model,a trustbased dynamic access control model for web services（DWTBAC） is proposed.To achieve the partial authorization,the model introduces some objective factors such as time weight,context and the strength of recommendation,improves the computational method of trust value and authorizes according to the mapping between trust value,trust level and the strength of permission.To prevent malicious behaviors,a punishment mechanism of service quality-based algorithm for the updating direct interaction experience value is proposed.The result of simulation shows that the new access control method,which achieves the dynamic change of trust value along with its behaviors and effectively prevents malicious behaviors,meets the demand of the dynamic and safety for web services access control.