Efficient Verifiable Key-Aggregate Keyword Searchable Encryption for Data Sharing in Outsourcing Storage

Abstract

In a secure data sharing system, users can selectively retrieve encrypted files by performing keyword search over the ciphertext of data. Most of the existing searchable encryption schemes can provide security protection for both data owner and users. Nevertheless, three pivotal issues need to be addressed. Firstly, the cloud might return a wrong result or incomplete result for some reasons, e.g., saving the computing resources. Secondly, users need to store massive keys to generate trapdoors and decrypt the ciphertext of data, which brings great challenges to users' key management. Thirdly, when users perform keyword search over a large number of files, they need to generate and submit massive trapdoors, which is unrealistic. Proceeding from these points, in this paper, we propose an efficient verifiable key-aggregate keyword searchable encryption (EVKAKSE) scheme. In this scheme, the data owner distributes only one aggregate key to users for keyword search, decryption and verification, who can use the aggregate key to generate a single trapdoor for keyword search over shared files. Generally, we define the requirements of the scheme, analyze the threat models and give a valid construction. Furthermore, our security analysis and experimental evaluation demonstrate that the scheme is efficient and secure.

Data Security and Privacy Protection for Cloud Storage: A Survey

“…The key-aggregate searchable encryption schemes [23] have been proposed to reduce the number of keys for users. Recently, Wang and Cheng [89] proposed an efficient verifiable key-aggregate keyword searchable encryption (EVKAKSE) system model. In this scheme, data owner uploads encrypted files and related encrypted potential keywords to the cloud server.…”

R-OO-KASE: Revocable Online/Offline Key Aggregate Searchable Encryption

“…The constant size of the aggregate key makes the KASE scheme more suitable for devices having limited storage resources, such as smart cards, IoT sensors. However, the existing KASE schemes [4,13,[18][19][20][21]31] use two pairing operations to generate a keyword ciphertext for each keyword to be attached with the document. Similarly, for decryption of ciphertext pairing operations are required.…”

“…The authors of [25] show that for different security levels (i.e., for 80 bits, 112 bits and 128 bits) and prime order groups, the pairing operation (on random group elements) requires significantly more time and power resource as compared to the group exponentiation (of a random group element with a random exponent) and multiplication operation. Therefore, the limited power resource of sensor nodes in IoT deployment does not support the expensive computational cost of the existing KASE schemes [4,13,[18][19][20][21]31]. The expensive computational cost of encryption and decryption phases make the existing KASE [4,13,[18][19][20][21]31] schemes infeasible to use in power-constrained devices.…”

“…Therefore, the limited power resource of sensor nodes in IoT deployment does not support the expensive computational cost of the existing KASE schemes [4,13,[18][19][20][21]31]. The expensive computational cost of encryption and decryption phases make the existing KASE [4,13,[18][19][20][21]31] schemes infeasible to use in power-constrained devices. Therefore, the KASE schemes [22,34,35] propose different solutions to generate keyword ciphertext without using expensive pairing operations and make the schemes practical for the Fig.…”

“…As compared to the previous solutions, the KASE [24] scheme supports multi-dimensional, multi-keyword searches on the encrypted dataset using a single trapdoor. Wang et al propose the verifiable KASE scheme in [31].…”