Outsourced KP-ABE with Chosen Ciphertext Security
Chao Li, Bo Lang, Jinmiao Wang · 2014
Key-Policy Attribute Based Encryption (KP-ABE) has always been criticized for its inefficiency drawbacks.Based on the cloud computing technology, computation outsourcing is one of the effective solution to this problem.Some papers have proposed their schemes; however, adversaries in their attack models were divided into two categories and they are assumed not to communicate with each other, which is obviously unrealistic.In this paper, we first proved there exist severe security vulnerabilities in these schemes for such an assumption, and then proposed a security enhanced Chosen Ciphertext Attack (SE-CCA) model, which eliminates the improper limitations.By utilizing Proxy Re-Encryption (PRE) and one-time signature technology, we also constructed a concrete KP-ABE outsourcing scheme (O-KP-ABE) and proved its security under SE-CCA model.Comparisons with existing schemes show that our constructions have obvious comprehensive advantages in security and efficiency.