A Novel and Efficient Secure Scheme for Cloud Storage Data with Key Vulnerability

Abstract

Cloud storage in public systems has become a major issue to control data access. A
pliable and most secure way to secure the data in the cloud severs for cloud storage is by
using Ciphertext-Policy Attribute-Based Encryption (CP-ABE). But, in existing scheme
the secure key distribution and verification is done by a single attribute authority which
take a lot of time. When it is done by the single attribute authority, it is like a single-point
play acquired in a big cloud storage system. There will be users who will be waiting for
secret keys for a long-time which result in the less efficiency of the system. Many solutions
have been proposed like multi authority scheme to overcome this problem but was unable
to overcome this problem. Therefore, this articleproposed a data confidentiality against
an adversary which knows the encryption key and has access to a large fraction of the
ciphertext blocks. To this end, we propose Bastion, a novel and efficient scheme that
guarantees data confidentiality even if the encryption key is leaked and the adversary has
access to almost all ciphertext blocks. We analyze the security of Bastion, and we
evaluate its performance by means of a prototype implementation. We also discuss
practical insights with respect to the integration of Bastion in commercial dispersed
storage systems. Our evaluation results suggest that Bastion is well-suited for integration
in existing systems since it incurs less than 5% overhead compared to existing
semantically secure encryption modes.