Paper Key : IRJ************142
Author: Aniyarasi.e
Date Published: 07 Oct 2023
Abstract
Cloud computing has become prevalent due to its nature of massive storage and vast computing capabilities. Ensuring a secure data sharing is critical to cloud applications. Recently, a number of identity-based broadcast proxy re-encryption (IB-BPRE) schemes have been proposed to resolve the problem. However, the IB-BPRE requires a cloud user (Alice) who wants to share data with a bunch of other users (e.g. colleagues) to participate the group shared key renewal process because Alices private key is a prerequisite for shared key generation. This, however, does not leverage the benefit of cloud computing and causes the inconvenience for cloud users. Therefore, a novel security notion named revocable identity-based broadcast proxy re-encryption (RIB-BPRE) is presented to address the issue of key revocation in this work. Adopting k-TAA schemes to PAYG model, th access bound k is decided by the prepayment amount and the service usage is tracked by the number of access times. However, this approach is impractical, since existing k-TAA schemes only allow an one-time access in an authentication. This work aims to bridge this gap in the literature by designing an efficient and secure authentication system for PAYG cloud computing, supporting flexible access controllability, user anonymity and public traceability. To achieve this, we propose new k-TAA primitive, called k-times anonymous pay-as-you-go authentication (k-TAA-PAYG), that allows users to access services for multiple times in an authentication as long as the number of their access times does not exceed k. We first formalize the definition and security model for k-TAA-PAYG scheme. Subsequently, we present a concrete construction of k-TAA-PAYG scheme, with the computational complexity as O(1) and the constant communicational cost. In a RIB-BPRE scheme, a proxy can revoke a set of delegates, designated by the delegator, from the re-encryption key. The performance evaluation reveals that the proposed scheme is efficient and practical.