Bilinear Diffie-Hellman Inversion Assumption Research Articles

PAC: Privacy preserving proxy re-encryption for access control in public cloud

ABSTRACT Proxy re-encryption is an essential prerequisite that facilitates a foreign entity (e.g., cloud server) to enforce the access of provisions of a document extended by one user to another user. While performing this task it is essential that the foreign entity does not learn any information about the actual document inside the encrypted envelop. In this paper, we present a scheme on Privacy-preserving Proxy Re-encryption for Access Control in Public Cloud, termed as PAC, that provides the proxy re-encryption of attribute-based encrypted data with receiver privacy. The proposed PAC scheme enables a proxy server to perform the re-encryption operation without learning anything about the data or the access policy. The PAC provides data confidentiality, and preserves receiver privacy. We show the PAC scheme adaptively secure against indistinguishability of ciphertext policy and chosen-plaintext attack (IND-CP-CPA) under the 2-Decisional Bilinear Diffie-Hellman Inversion assumption. The scheme is implemented on Google cloud instance and the experimental results show that the PAC scheme is storage and computation-efficient when compared to other related schemes.

Revocable hierarchical identity-based broadcast encryption

Hierarchical Identity-Based Broadcast Encryption (HIBBE) organizes users into a tree-like structure, and it allows users to delegate their decryption ability to subordinates and enable encryption to any subset of users while only intended users can decrypt. However, current HIBBE schemes do not support efficient revocation of private keys. Here, a new primitive called Revocable Hierarchical Identity-Based Broadcast Encryption (RHIBBE) is formalized that allows revocation of the HIBBE. Ciphertext indistinguishability is defined against the selectively Bounded Revocable Identity-Vector-Set and Chosen-Plaintext Attack (IND-sBRIVS-CPA). An IND-sBRIVS-CPA secure RHIBBE scheme is constructed with efficient revocation on prime-order bilinear groups. The unbounded version of the scheme is also shown to be secure but a little weaker than the former under the decisional n-Weak Bilinear Diffie-Hellman inversion assumption.

A restricted proxy re‐encryption with keyword search for fine‐grained data access control in cloud storage

SummaryFor fine‐grained data access control in cloud computing, for the first time, we introduce a new concept called restricted proxy re‐encryption with keyword search, which combines the function of proxy re‐encryption with keyword search and that of threshold cryptosystem. To demonstrate this concept, we present the formal syntax for restricted proxy re‐encryption with keyword search, the security model, and a concrete construction. In our scheme, we take advantage of the techniques of threshold cryptosystem to restrict the capacity of the proxy cloud server, and in the meantime, we let the proxy cloud server can only re‐encrypt the data containing a specified keyword, which matches the trapdoor from delegatee to provide an accurate access control for users. While in this process, the proxy cloud server learns nothing about the contents of data and keyword. Our scheme is proved to be semantically secure under the modified bilinear Diffie–Hellman assumption and the q‐decisional bilinear Diffie–Hellman inversion assumption in the random oracle model. Finally, we apply the techniques in our scheme to some practical problems. Copyright © 2016 John Wiley & Sons, Ltd.

Efficient Identity-based Broadcast Encryption without Random Oracles

We propose a new efficient identity-based broadcast encryption scheme without random oracles and prove that it achieves selective identity, chosen plaintext security. Our scheme is constructed based on bilinear Diffie-Hellman inversion assumption and it is a good efficient hybrid encryption scheme, which achieves O (1) -size ciphertexts, public parameters and constant size private keys. In our scheme, either ciphertexts or public parameters has no relation with the number of receivers, moreover, both the encryption and decryption only require one pairing computation. Compared with other identity-based broadcast encryption schemes, our scheme has comparable properties, but with a better efficiency.

Constructing Efficient Certificate-based Encryption with Paring

The certificate-based encryption (CBE) is a new PKC paradigm which combines traditional public-key encryption (PKE) and identity based encryption (IBE) while preserving their features. CBE provides an efficient implicit certificate mechanism to eliminate third-party queries for the certificate status and to simply the certificate revocation problem. Therefore, CBE can be used to construct an efficient PKI requiring fewer infrastructures. In addition, it also solves the key escrow problem and key distribution problem inherent in IBE. In this paper, we construct an efficient CBE scheme with paring and prove it to be CCAsecure in the random oracle model based on the hardness of the Bilinear Diffie-Hellman Inversion assumption. When compared with other existing CBE schemes, our scheme has obvious advantage in the computation performance.