Introduction

The continuous evolution and pervasive application of communication technology, network technology, and computing technology have boosted interconnection of everything and ubiquitous sharing of information. With the continuous emergence of new information services, user data is frequently exchanged across systems, ecologies, and countries. User data contains a large amount of personal privacy information, which is retained intentionally or unintentionally in different information systems. At the same time, the data protection capabilities and protection strategies of each information system are very different, which leads to cask principle and a dramatic increase in the risk of privacy leakage. Protection of personal information and the governance of privacy abuse have become a worldwide problem.