Open Access
ARTICLE
An Efficient Ciphertext-Policy Attribute-Based Encryption Scheme with Policy Update
Changji Wang1, *, Yuan Yuan2
1 School of Information Science and Technology, Guangdong University of Foreign Studies, Guangzhou, 510006, China.
2 School of Mathematics and Statistics, Guangdong University of Foreign Studies, Guangzhou, 510006, China.
* Corresponding Author: Changji Wang. Email: .
Computers, Materials & Continua 2020, 63(2), 1031-1041. https://doi.org/10.32604/cmc.2020.06278
Received 30 January 2019; Accepted 22 January 2020; Issue published 01 May 2020
Abstract
Ciphertext-policy attribute-based encryption (CP-ABE) is a promising
cryptographic solution to the problem for enforcing fine-grained access control over
encrypted data in the cloud. However, when applying CP-ABE to data outsourcing
scenarios, we have to address the challenging issue of policy updates because access
control elements, such as users, attributes, and access rules may change frequently. In this
paper, we propose a notion of access policy updatable ciphertext-policy attribute-based
encryption (APU-CP-ABE) by combining the idea of ciphertext-policy attribute-based key
encapsulation and symmetric proxy re-encryption. When an access policy update occurs,
data owner is no longer required to download any data for re-encryption from the cloud,
all he needs to do is generate a re-encryption key and produce a new encapsulated
symmetric key, and then upload them to the cloud. The cloud server executes re-encryption
without decryption. Because the re-encrypted ciphertext is encrypted under a completely
new key, users cannot decrypt data even if they keep the old symmetric keys or parts of the
previous ciphertext. We present an APU-CP-ABE construction based on Syalim et al.’s
[Syalim, Nishide and Sakurai (2017)] improved symmetric proxy re-encryption scheme
and Agrawal et al.’s [Agrawal and Chase (2017)] attribute-based message encryption
scheme. It requires only 6 bilinear pairing operations for decryption, regardless of the
number of attributes involved. This makes our construction particularly attractive when
decryption is time-critical.
Keywords
Cite This Article
C. Wang and Y. Yuan, "An efficient ciphertext-policy attribute-based encryption scheme with policy update,"
Computers, Materials & Continua, vol. 63, no.2, pp. 1031–1041, 2020. https://doi.org/10.32604/cmc.2020.06278