Efficient k-Resilient Public Key Authenticated Encryption with Keyword Search

Traditional encryption prioritises confidentiality but complicates search operations, requiring decryption before searches can be conducted. The public key encryption with keyword search (PEKS) scheme addresses this limitation by enabling authorised users to search for specific keywords within encrypted data without compromising the underlying encryption. This facilitates efficient and secure data retrieval without the need to decrypt the entire dataset. However, PEKS is susceptible to the keyword guessing attack (KGA), exploiting the deterministic nature of the PEKS trapdoor so that the adversary can correctly guess the keyword encrypted in a trapdoor. To enhance PEKS security to counter a KGA, various schemes have been proposed. A notable one is public key authenticated encryption with keyword search (PAEKS). PAEKS combines authentication and encryption with keyword-based search functionalities, ensuring data source authentication, encrypted information security, and keyword-based searches. However, many existing PAEKS schemes rely on computationally exhaustive bilinear pairing. In this paper, we propose a PAEKS scheme based on k-resilient identity-based encryption without bilinear pairing. By using the provable security approach, we show that our proposed PAEKS scheme satisfies both ciphertext privacy and trapdoor privacy. We present a comparison of the computation cost of our proposed PAEKS scheme with the existing PAEKS schemes and highlight its efficiency, particularly in the Test algorithm, where it achieves the fastest execution time. By performing experiments using the real-world Enron Email dataset, we show that the proposed scheme is efficient.