I. Introduction
With the rapid development of Internet of Things, IoT terminal devices have been embedded in all aspects ofour lives, and people have leit a large amount of data information on the Internet through IoT terminal devices. Many cases show that private information about individuals can be discovered even after a large amount of harmless data has been collected. Criminals use these private information to conduct fraud and other acts, which will bring losses or even threats to individuals and their family lives. Therefore, the privacy protection of personal data has attracted extensive attention from industry and academia.