Novel Constructions for Ciphertext-Policy Attribute-Based Searchable Encryption

Abstract

More often, cloud services are being used for out-sourcing data storage. Nonetheless, as storage providers are untrustworthy, two major security concerns for data owners are confidentiality and access control. A naive solution to achieve these security goals is to encrypt before outsourcing the data to the cloud. However, such approach entails a major problem for data consumers: searching over unintelligible data becomes quite difficult. In this context, Searchable Encryption (SE) is a powerful cryptographic technique that lets data owners store encrypted data on untrusted external servers while keeping the ability to perform searching and retrieval tasks from the encrypted format. In this paper, we present two novel constructions for searching over encrypted data on the basis of Attribute-Based Searchable Encryption (ABSE). Our constructions are implemented over asymmetric pairings (Type-III), enabling SE deployments for security levels higher than the common and obsolete 80-bit security found in the literature. The proposed constructions consider the two most common realizations of Attribute-Based Encryption (ABE) for the access structure: tree- and matrix-based. The experimental validation and evaluation over the LISA benchmark revealed the suitability of ABSE in practical applications, its correctness, and efficacy.