SecCloudSharing: Secure data sharing in public cloud using ciphertext‐policy attribute‐based proxy re‐encryption with revocation

Abstract

An efficient cryptography mechanism should enforce an access control policy over the encrypted data to provide flexible, fine-grained, and secure data access control for secure sharing of data in cloud storage. To make a secure cloud data sharing solution, we propose a ciphertext-policy attribute-based proxy re-encryption scheme. In the proposed scheme, we design an efficient fine-grained revocation mechanism, which enables not only efficient attribute-level revocation but also efficient policy-level revocation to achieve backward secrecy and forward secrecy. Moreover, we use a multiauthority key attribute center in the key generation phase to overcome the single-point performance bottleneck problem and the key escrow problem. By formal security analysis, we illustrate that our proposed scheme achieves confidentiality, secure key distribution, multiple collusions resistance, and policy-or attribute-revocation security. By comprehensive performance and implementation analysis, we illustrate that our proposed scheme improves the practical efficiency of storage, computation cost, and communication cost compared to the other related schemes. KEYWORDSattribute-level revocation, attribute-based access control, CP-ABE, policy-level revocation, public cloud storage INTRODUCTIONCloud computing emerges as a new paradigm of computing that provides elasticity, scalability, and multitenancy on demand pay-per-use service model. 1 Specifically, cloud storage services enable a data owner to host data in the cloud, and enable a consumer to access the data through cloud server. 2 The adoption of a cloud storage service (eg, Dropbox, Google Drive, Microsoft and OneDrive) for storing, managing, and sharing the data has been gained significant attention in the real world. 3 However, privacy and security issues related to the user's data pose various challenges regarding data access control that impede the cloud storage system from wide adoption. 4-7 To prevent the unauthorized access of the sensitive data, a common method is to encrypt the data before uploading it to the cloud server. 8 The traditional public key encryption, 9 identity-based encryption (IBE), 10-12 and homomorphic encryption 13,14 cannot be directly used to impose the access control over the encrypted data in cloud environment. These methods ensure that the encrypted data can be decrypted by a single user, thus decreasing the flexibility and scalability of data access control in cloud environment.Int J Commun Syst. 2018;31:e3494.wileyonlinelibrary.com/journal/dac

Secure Data Sharing and Customized Services for Intelligent Transportation Based on a Consortium Blockchain

“…The computational overhead mainly includes encryption, reencryption, decryption and re-encrypted ciphertext decryption (re-decryption). Table 3 shows the comparison results of our scheme with references [44], [45] and [46], where T B is the bilinear operation, T E is the exponential operation on the multiplicative cyclic group. Compared with the above two operations, the multiplication operation's computation cost is very small and can be ignored.…”

“…We use the hash function to sign the ciphertext. However, in references [44], [45] and [46], there is only data encryption and no signature process. Our scheme not only protects the integrity and non-repudiation of data, but also takes less time.…”

“…In the process of re-encryption in Ref. [45], the proxy needs to frequently verify the user's token, resulting in a large computational overhead. Figure 8(c) shows that as the number of attributes increases, the computational cost of our scheme in the decryption process is the least.…”

“…The communication overhead in the process of secure data sharing and customized services provided by the service sector mainly includes system parameters, the private key, the ciphertext and the re-encrypted ciphertext. Table 4 shows the comparison results of communication cost between our scheme and references [44], [45] and [46].…”

“…In our scheme, ciphertext contains the signatures, so the communication overhead is slightly larger than that of Ref. [45], but it has certain advantages compared with Ref. [44] and Ref.…”