Mid Sweden University

In the following years, the desktop-based applications will be changed to cloud computing gradually. Since all users' profile and context data will be stored on the service supplier side based on their ID. ID is becoming a security bottleneck: attackers can trace all other information via user ID. Increasingly, a simple service may be involved in a chain of service clouds; each cloud is able to access data in its cloud without the control of any technology. With ID and password cross utilization in clear text, leakage of ID profile and password in one cloud may propagate to the whole cloud chain. Without proper protection, the success of cloud computing will be threatened by ID privacy leakage. In this paper, privacy preserved ID profile utilizing protocol (PPID) is proposed to prevent this privacy flaw. PPID together with its extension ID anonymity protocol (IDA) separate ID and services. With these two protocols, threaten from crash of whole cloud chain caused by ID privacy leakage is minimized.