Abstract: In order to solve the problem of user information leakage, this paper proposed the lightweight protection method for user information. The digital contents such as ID number and phone number in the user information are encoded by the mask, stored with other information and decoded when used. The mask can be calculated by server flags, time and so on. When user information is leaked, only the encoded information will be exposed. By calculating the digital contents in the leaked information with the real digital content to get the mask, the source and time of information leakage can be traced, which can achieve the effect of anti-leakage and traceability.

Key words: user information, personal information, information security, information protection, information leakage, information source