An Efficient Privacy-Preserving Attribute-Based Encryption with Hidden Policy for Cloud Storage

Abstract

Cloud storage is one of the most widely-used storage services, because it can provide users with unlimited, scalable, low-cost and convenient resource services. When data is outsourced to cloud for storage, data security and access control are the two essential issues that need to be addressed. Attribute-based encryption (ABE) scheme can provide sufficient data security and fine-grained access control for cloud data. As more and more attention is drawn to privacy protection, privacy preservation becomes another urgent issue for cloud storage. In ABE, since the access policies are generally stored in clear text, it will lead to the disclosure of users’ privacy. Some works sacrifice computational efficiency, key length or ciphertext size for privacy concerns. To solve these problems, this paper proposes an efficient privacy-preserving attribute-based encryption scheme with hidden policy for outsourced data. Using the idea of Boolean equivalent transformation, the proposed scheme achieves fast encryption and privacy protection for both data owner and legitimate visitors. In addition, the proposed scheme can satisfy constant secret key length and reasonable size of ciphertext requirements. We also conduct theoretical security analysis, and carry out experiments to prove that the proposed scheme has good performance in terms of computation, communication and storage overheads.

Access control scheme based on blockchain and attribute-based searchable encryption in cloud environment

“…Reference [23] proposes an attribute-based encryption scheme for keyword searches based on policy hiding to prevent keywordguessing attacks. Reference [24] proposes a cloud storage scheme with attribute policy hiding based on the "AND" gate access structure, which implements obfuscated attributes into the original access policy for user authentication. However, [22][23][24] are not blockchain-based, and ignore the security threats caused by third parties.…”

“…Reference [24] proposes a cloud storage scheme with attribute policy hiding based on the "AND" gate access structure, which implements obfuscated attributes into the original access policy for user authentication. However, [22][23][24] are not blockchain-based, and ignore the security threats caused by third parties. Reference [25] proposes a policy-hiding blockchain access control scheme based on CP-ABE.…”

“…In Table 2, we compare the functional characteristics of the proposed scheme and schemes [24,25,28,29,31,32]. It can be seen that most schemes only support some functions.…”

“…For example, schemes [28,29,32] support attribute revocation and keyword search, but not policy hiding. Schemes [24,25,31] support policy hiding, but not attribute revocation. In addition, only this scheme and scheme [32] support proxy decryption calculation, and only schemes [25,32] apply blockchain technology.…”

“…From the communication point of view, we compare the storage cost of the proposed scheme with schemes [24,28,29], as shown in Table 3. |G|, |G T | represent the size of the elements in G and G T , respectively.…”