Delegation-based conversion from CPA to CCA-secure predicate encryption. (3rd May 2020)

• Record Type: Journal Article
• Authors: Nandi, Mridul; Pandit, Tapas
• Is Part Of: International journal of applied cryptography. Volume 4:Number 1(2020)
• Page Start: 16
• Page End: 35
• Publication Date: 2020-05-03
• Subjects: predicate encryption -- delegation -- CPA to CCA conversion; Data encryption (Computer science) -- Periodicals; Cryptography -- Periodicals; Computer security -- Periodicals; 652.8
• Languages: English
• ISSNs: 1753-0563

Abstract

In 2011, Yamada et al. proposed CPA to CCA-secure conversions for attribute-based encryption (ABE) based on the properties, verifiability and delegation. Later, the verifiability-based conversion was generalised from ABE to predicate encryption (PE) by Yamada et al. (2012) and Nandi et al. (2017). We observe that for bilinear-pairing based PE schemes, the cost of CCA-decryption blows up to the double of the cost of CPA-decryption due to verifiability testing. Therefore, the conversion based on delegation is mostly acceptable whenever a delegation-based conversion is available for the primitive PE scheme. In this paper, we investigate a generic delegation-based conversion from CPA to CCA-secure predicate encryption schemes. Our conversion generalises the delegation-based conversion of Yamada et al. (2011) from ABE to PE. We show that our conversion captures many subclasses of PE, e.g., (hierarchical) inner-product encryption, (doubly-)spatial encryption and functional encryption for regular languages.