Abstract: At present,most of the security assessment works of the information system are based on the single imformation system,and its security status is evaluated according to each attribute hierarchy.There are few methods to evaluate the security level of information system for system group.According to the security requirements of information system,a security level evaluation method based on system group was proposed.Taking into account the grey clustering analysis method of grey system theory,some evaluation objects are divided into several grades by using the whitening weight function,which is suitable for the system analysis of complex structure,high uncertainty and lack of effective information,In this paper,we used the whitening weight function to determine the level of security evaluation of information system.Firstly,from the point of view of the information system,a fast and efficient K-mean clustering algorithm is used to determine the whitenization weight function.Secondly,the grey level grey clustering coefficient of each information system is obtained by using the whitening weight function.Finally,we can get the security level of each information system.The results show that this method can effectively evaluate the security level of information systems group.

Key words: Whitening weight function,Grey clustering,System group evaluation,Information security