Contents I. Introduction
The demand for collaborative computing involving mobile devices such as smartphones and IoT devices has witnessed a significant surge. For instance, smart home devices aggregate and analyze user data to offer improved services [1], and edge devices contribute local data to federated learning [2]. Consequently, data sharing and utilization on mobile devices have emerged as a crucial issue. As individuals become increasingly aware of the value of their data and data commodification progresses, it is imperative that data sharing and usage occur in the form of commercial services. European Union's General Data Protection Regulation (GDPR) [3] confers several specific principles for data services: i. ”Privacy by design”: the data sharing mode has to be privacy-preserving to guarantee no visibility from the public perspective; ii. ”Right to access”: Data providers have the right to be informed about how and why the data receivers are using the data they share, and data are used in a manner consistent with the intended execution; iii. ”Right to be forgotten”: when the data service needs to be terminated at any time, it is essential to incorporate a withdrawal mechanism that ensures the buyer's inability to access the data any longer; iv. ”Right to data portability”: data should be regularized in a structured, commonly used and machine-readable format to facilitate sharing. It requires that data usage should have the ability to be migrated into multiple devices or operating systems.
