A Survey of Crowdsensing and Privacy Protection in Digital City

The key pillar of developing digital city is the ubiquitous sensing of people and the environment. Crowdsensing requires a large number of users to participate in the collection of sensing data, and these data may carry sensitive information, such as identity and location related to the users or sensing object. If this information is eavesdropped, intercepted, and leaked, this may seriously harm the interests of individuals, organizations, and even countries. Therefore, from a privacy perspective, users may be reluctant to open data. While relying on mobile devices used by a large number of ordinary users as the basic sensing unit, it is necessary to include a variety of communication methods to realize the distribution of sensing tasks and to collect the sensing data. Then, to complete the complex crowdsensing tasks, it is important to ensure privacy security in the context of crowdsensing because it is a key problem. In this article, we comb through the development status of crowdsensing in the digital city, emphatically analyze the privacy protection in crowdsensing under the background of digital city, and qualitatively evaluate the existing privacy protection technologies for crowdsensing. Finally, this article presents research challenges and future directions that should be addressed to improve the performance of privacy protection technologies for crowdsensing systems.