On the Design of a Searchable Encryption Protocol for Keyword Search using Proactive Secret Sharing

Searchable encryption allows users to perform search operations on encrypted data before decrypting it first. Secret sharing is one of the most important cryptographic primitives used to design an information theoretic scheme. Nowadays cryptosys-tem designers are providing a facility to adjust the security parameters in real time to circumvent AI-enabled cyber security threats. For long term security of data which is used by various applications, proactive secret sharing allows the shares of the original secret to be dynamically adjusted during a specific interval of time. In proactive secret sharing, the updation of shares at regular intervals of time is done by the servers (participants) and not by the dealer. In this paper, we propose a novel proactive secret sharing scheme where the shares stored at servers are updated using preshared pairwise keys between servers at regular intervals of time. The direct search of words over sentences using the conjunctive search function without the generation of any index is possible using the underlying querying method.