Published Paper Details:

secure data storage and retrieval is the best research directions in cloud. Though lots of searchable encryption scheme have been proposed some of them support efficient retrieval over the documents. Which are encrypted based on their attributes. In this paper a hierarchical attribute based encryption scheme is designed for a data collection. A set of documents is encrypted together if they share an integrated access structure. Compared with the CP policy attribute based encryption schemes, both the cipher text storage space and time costs of encryption and decryption are saved. Then, an index structure named attribute based retrieval features tree is constructed for the document collection based on the TF-IDF model and the documents attributes. A depth first search algorithm for the attribute based retrieval features tree is designed to better the search efficiency which can be further improved by parallel computing. Except for the documents collections in our scheme can be applied to other data sets by modifying the attribute based retrieval features tree slightly. A thorough analysis and series of experiments performed to illustrate the security and efficiency of the proposed scheme.