Abstract:

Users of cloud storage often outsource their data to cloud servers to save local storage resources.However, cloud storage data is out of the user’s physical control, which may lead to malicious theft or disclosure of private data on cloud.At present, dynamic searchable encryption schemes are mostly based on symmetric searchable encryption, which need to establish a secure key sharing channel in advance, and cannot be directly applied to data sharing in cloud storage scenarios.For the secure sharing scenario of multi-party data in cloud storage, a dynamic multi-keyword searchable encryption scheme was proposed.The forward index was constructed by a cuckoo filter to enable data owners to perform documents and index dynamic updates.The conjunctive multi-keywords search was supported by combining bilinear pairing with Lagrangian interpolation polynomials.To reduce the computational overhead in the ciphertext retrieval phase, a combination of inverted index and forward index was constructed to improve the retrieval efficiency of cloud server.This scheme is provably secure with the indistinguishability in adaptively chosen keyword attack under decision linear Diffie-Hellman problem.Simulation experiments were conducted to analyze the execution efficiency of the scheme for keyword search and index update in different datasets.The results show that the scheme effectively avoids the linear correlation between the retrieval time and the number of ciphertexts, and reduces the computational overhead in the update operation with a large amount of data.

Key words: searchable encryption, cloud storage, cuckoo filter, inverted index