SECURE KEYWORD SEARCH AND KEY MANAGEMENT SCHEME IN CLOUD ENVIRONMENTS

Abstract

A cloud server may safely conduct a keyword search over data encrypted with different public keys on behalf of assigned users thanks to a keyaggregate keyword retrieval primitive. The best approach for the above issue is to encrypt distinct files using various public keys, but just send each user a single or constant-size secret key that is used to produce the trapdoor when searching for keywords over the encrypted files. However, existing key-aggregate searchable encryption schemes are insecure against keyword guessing attacks, which result in the privacy leakage of keyword ciphertext and trapdoor. In this paper, we for the first time formulate a secure and efficient keyaggregate searchable encryption for cloudassisted IoT applications, which not only enables a data owner to securely share the selected documents to multiple users, but also supports data users in delegating the capability of keyword search to a cloud server for searching the desired documents without leaking any privacy of keyword ciphertext and trapdoor. Following that, the suggested scheme's security is properly specified and shown to be safe from indistinguishable selective-file chosen keyword attacks. Our developed scheme's security specification is codified using the standard model. We also prove it to be secure with a strict security proof. The flexibility and practicability of the formulated scheme is also demonstrated by theoretical evaluations and experimental simulations.