A Review of Motion Data Privacy in Virtual Reality

As the metaverse grows with the advances of new technologies, a number of researchers have raised the concern on the privacy of motion data in virtual reality (VR). It is becoming clear that motion data can reveal essential information of people, such as user identification. However, the fundamental problems about what types of motion data, how to process, and on what ranges of VR applications are still underexplored. This work summarizes the work of motion data privacy on these aspects from both the fields of VR and data privacy. Our results demonstrate that researchers from both fields have recognized the importance of the problem, while there are differences due to the focused problems. A variety of VR studies have been used for user identification, and the results are affected by the application types and ranges of involved actions. We also review the biometrics work from related fields including the behaviors of keystrokes and waist as well as data of skeleton, face and fingerprint. At the end, we discuss our findings and suggest future work to protect the privacy of motion data.