Fully Secure Cipertext-Policy Hiding CP-ABE

• Main Authors: LAI, Junzuo, DENG, Robert H., LI, Yingjiu
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2011
• Subjects: Ciphertext Policy Attribute-Based Encryption; Predicate Encryption; Dual System Encryption; Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/1416; https://ink.library.smu.edu.sg/context/sis_research/article/2415/viewcontent/FullySecureCipertextPolicy_2011.pdf
• Institution: Singapore Management University

In ciphertext-policy attributed-based encryption (CP-ABE), each ciphertext is labeled by the encryptor with an access structure (also called ciphertext policy) and each private key is associated with a set of attributes. A user should be able to decrypt a ciphertext if and only if his private key attributes satisfy the access structure.The traditional security property of CP-ABE is plaintext privacy, which ciphertexts reveal no information about the underlying plaintext. At ACNS’08, Nishide, Yoneyama and Ohta introduced the notion of ciphertext-policy hiding CP-ABE. In addition to protecting the privacy of plaintexts, ciphertext-policy hiding CP-ABE also protects the description of the access structures associated with ciphertexts. They observed that ciphertext-policy hiding CP-ABE can be constructed from attribute-hiding inner-product predicate encryption (PE), and presented two constructions of ciphertext-policy hiding CP-ABE supporting restricted access structures, which can be expressed as AND gates on multi-valued attributes with wildcards. However, their schemes were only proven selectively secure.In this paper, we first describe the construction of ciphertext-policy hiding CP-ABE from attribute-hiding inner-product PE formally. Then, we propose a concrete construction of ciphertext-policy hiding CP-ABE supporting the same access structure as that of Nishide, Yoneyama and Ohta, but our scheme is proven fully secure.