Abstract: In pervasive computing environment， trust management have become a cornerstone for information security.For study the fuzziness of subject trust and the dynamics of trust relationships between various subjects， the paper presents a model to evaluate user’s trustworthiness based on fuzzy theory of fuzzy mathematics.This model introduces the fuzzy theory to the fuzziness and dynamics of trust relationships，and evaluates the factors which affect the trust subject， then gains a total trustworthiness to make sure that whether it may trust the subject for alternation.The model can evaluate the user’s trustworthiness completely，security and reliability of pervasive behavior can be guaranteed greatly，and provides a new method to handle uncertainty in trust management for pervasive computing.

Key words: trust management, fuzzy theory, trustworthiness evaluation, fuzzy integration evaluation

摘要： 信任管理是当前普适环境中信息安全研究的热点。为了解决主观信任的模糊性和主体之间信任关系的动态性，在模糊数学中的模糊理论的基础上，提出了一个用户信任度的评估模型。该模型是将模糊理论应用到信任关系的不确定性和动态性上，对影响信任主体的主要因素进行综合评估，得出一个总的信任度来确定是否可以信任主体以便进行交互。该模型可以全面地评估用户的信任度，很大程度上保证了普适行为的安全可靠，为处理普适计算的信任管理的不确定研究提供了一个新的方法。

关键词: 信任管理, 模糊理论, 信任度评估, 模糊综合评估