关键词: 云计算, 隐私Petri网（PPN）, 用户行为, 隐私泄露, 性能分析

Abstract: The user’s behavior, especially these exists privacy disclosure, which is based on Privacy Petri Net（PPN） under the cloud computing environment is analyzed, and then the method to acquire the relevant interface when the user monitors the application software is introduced. In addition, the characteristics of user’s behavior which exists privacy data leakage are analyzed. The normal QQ software and the malicious QQ software which is infected virus are running respectively, and the similarities and differences between the calling sequences are monitored. According to the calling sequences, the global PPN model in the modeling software is set up, and then analysis and comparison is made. Finally, the analysis of the user’s behavior is tested and relevant algorithm is analyzed. Furthermore, qualitative analysis and quantitative analysis are made, including computing the value of its four indices：possibility, severity, manipulability, and crypticity. As the results show that compared with the normal QQ software, the malicious QQ software not only accesses other data beyond its authority but also tampers its rights without permission in order to obtain the corresponding data. Besides, the malicious software which exists privacy data leakage usually has strong ability to access important resources, particularly some even send privacy data to remote host through the network.

Key words: cloud computing, Privacy Petri Net（PPN）, user behavior, privacy leakage, performance analysis