点对点网络中运用云理论的信任域模型

摘要

As the fuzziness and uncertainty of trust could not be described and calculated exactly in peer-to-peer network, a trust model using domain concept was designed firstly, including management, transmission and expression of trust degree. In the calculation of the peer global trust value, dynamic weight function was introduced. Then, each qualitative existed trust degree was mapped to quantitative and variable cloud droplet by using cloud theory, and numerical characteristics of every cloud were calculated with different weight. In Matlab and Microsoft Visual C+ +, similarity with standard cloud was calculated, the cloud which was the most similar to the standard kept furthest fuzziness and uncertainty of trust in peer-to-peer network, and ultimately the request peer trust degree was determined. The result shows that the trust model based on domain concept and cloud theory describes and calculates the trust in peer-to-peer network, and it also has strong ability against the attack.%针对点对点网络中信任的模糊性和随机性难以刻画和计算的特点,首先运用域的概念设计一个信任模型,包括可信度的管理、传递和表示.在计算对等点的全局可信度时引入动态权重函数,再运用云理论将每个已存在的可信度映射为定量的可细微变化的不同云滴,并计算不同权值下其云的数字特征.在Microsoft Visual C++和Matlab环境下,计算与标准概念云的相似度,相似度最大的云最大限度地保留了点对点网络中信任的随机度和模糊度,其所对应的权重最终确定了请求对等点的可信度.结果表明,运用域的概念和云理论的信任模型较好地表征和计算了点对点网络中的信任,具有较强的抗攻击能力.