Attribute Based Proxy Re-encryption for Data Confidentiality in Cloud Computing Environments

To ensure data confidentiality and fine-grained access control in cloud computing environments, a recent study proposed system model using Key Policy-Attribute Based Encryption(KP-ABE) and Proxy Re-Encryption(PRE). But, existing work has effected the violation of data confidentiality through collusion attack of revoked user in system and cloud server. To resolve this problem, we propose system model that store and divide data file into header, body. In addition, our scheme selectively delegate decryption right using Type-based Proxy re-encryption.