Comments on “P2AE: Preserving privacy, accuracy, and efficiency in location-dependent mobile crowdsensing”

<p>In 2021, Jiang et al. proposed P2AE, a privacy preserving protocol in location-dependent mobile crowdsensing (DOI: 10.1109/TMC.2021.3112394). One of the core techniques behind their scheme is a location-based symmetric key generation algorithm, which enables the service requestor and the mobile nodes in the task area to generate the same key themselves without revealing the location information. However, in this comment, we will point out a flaw in their location-based symmetric key generation algorithm, which indicates that P2AE does not work. In addition, we propose a novel approach to achieve the location-based symmetric key generation using a witness encryption scheme. This approach is feasible, but is currently inefficient due to the inefficiency of the underlying witness encryption scheme.</p>