and Data 61, CSIRO KANCHANA THILAKARATHNA, University of Sydney and Data 61, CSIRO ARUNA SENEVIRATNE, University of New South Wales and Data 61, CSIRO Mixed reality (MR) technology development is now gaining momentum due to advances in computer vision, sensor fusion, and realistic display technologies. With most of the research and development focused on delivering the promise of MR, there is only barely a few working on the privacy and security implications of this technology. is survey paper aims to put in to light these risks, and to look into the latest security and privacy work on MR. Speci cally, we list and review the di erent protection approaches that have been proposed to ensure user and data security and privacy in MR. We extend the scope to include work on related technologies such as augmented reality (AR), virtual reality (VR), and human-computer interaction (HCI) as crucial components, if not the origins, of MR, as well as numerous related work from the larger area of mobile devices, wearables, and Internet-of-ings (IoT). We highlight the lack of investigation, implementation, and evaluation of data protection approaches in MR. Further challenges and directions on MR security and privacy are also discussed. 2 works from Scopus by separately searching for AR/VR/MR works with security and privacy from Google Scholar, IEEE Xplore, ACM Digital Library, and other speci c venues covering computer vision, human-machine interfaces, and other related technologies.
Previous Surveys and Meta-analysesEarly surveys on AR and MR, have been focused on categorizing the existing technologies then. In 1994, a taxonomy for classifying mixed reality displays based on the user-interface -from monitor-based video displays to completely immersive environments -were presented and these devices were plo ed along a reality-virtuality continuum . On the other hand, in contrast to this one-dimensional continuum, two di erent classi cations for mixed reality were also presented: (1) a two-dimensional categorization of shared space or collaborative mixed reality technologies according to concepts of transportation 1 and arti ciality 2 , and (2) a one-dimensional classi cation based on spatiality 3 (Benford et al. 1996).Succeeding endeavours have focused on collecting all relevant technologies necessary to AR and VR. e various early challenges -such as matching the real and virtual displays, aligning the virtual objects with the real world, and the various errors that needs to be addressed such as optical distortion, misalignment, and tracking -have been discussed in broad (Azuma 1997). It was complemented with a following survey that focuses on the enabling technologies, interfacing, and visualization (Azuma et al. 2001). A much more recent survey updated the existing challenges to the following: performance, alignment, interaction, mobility, and visualization (Rabbi and Ullah 2013). Another one looked into a speci c type of AR, mobile AR, and looked into the di erent technologies that enable mobility with AR (Chatzopoulos et a...