Ciphertext-policy attribute based encryption with large attribute universe

Abstract

Ciphertext-policy attribute-based encryption(CP-ABE) has become a crucial technical for cloud computing in that it enables one to share data with users under the access policy defined by himself. Generally, the universe of attributes is not fixed before the system setup in practice. So in this paper, we propose a CP-ABE scheme with large attribute universe based on the scheme presented by Chen et al. The number of attributes is independent of the public parameter in our scheme, and it inherents the excellent properties of both constant ciphertext and constant computation cost.