关键词: 改进DS理论, 三角模糊数, 信息安全, 双重模糊, 威胁程度

Abstract: In order to reduce the evaluation error caused by fuzzy data in information security assessment, an improved double fuzzy safety evaluation algorithm is proposed, which is based on triangular fuzzy number and improved evidence reasoning. This algorithm considers the uncertainty of information security system and experts’ subjective. Firstly, The performance of the information security system can cause on the evaluation of experts. The consequences are calculated with improved DS theory method. Secondly, the experts’ opinions are polymerized with the method of triangular fuzzy number. On the basis of risk calculation formula, the severity of threats is calculated. The results calculated by the improved double fuzzy evaluation, considering the uncertainty of the information security system and subjective uncertainty, are more subjective than which by the single fuzzy evaluation method. The necessity and effectiveness of the method are verified through examples.

Key words: improved evidence reasoning, triangular fuzzy number, information security, double fuzzy, threat degree