Privacy-Preserving Wildcards Pattern Matching Protocol for IoT Applications

With the continuous development of the Internet of Things (IoT), various IoT devices create an incomprehensible amount of data all the time. However, the IoT devices have limited computing and storage resources and are difficult to process massive data locally, so they often introduce servers to help them for calculating or analyzing data. At present, the “IoT + Cloud” mode has been widely accepted. How to protect users' privacy in the public cloud environment has become critical. Among the common methods of processing data in the server, pattern matching is an important one which aims to identify the appearance and location of a string (called pattern) within a larger string or text. There are a lot of studies on privacy-preserving pattern matching protocols, but most protocols are constructed using heavy public-key cryptographic operations, which are not applicable to IoT devices. In this paper, we propose a new protocol using secret sharing and oblivious transfer (OT) and latter improve its efficiency with OT extension, so it is very efficient for lightweight IoT devices. In addition, our protocol also supports query with wildcards which can be used for the batch search. This protocol is provable-secure against honest-but-curious adversaries. Both the theoretical and experimental results show that our protocol can be used in real-world IoT applications.