International Journal of Science, Engineering and TechnologyAuthors: Yash Sukhdev Jadhav, Professor Bangar A.P., Professor Bhosale S.B., Dr. A. A. Khatri
Abstract: Storing data with a single cloud provider creates a single point of failure and ties an organisation to one vendor’s security posture. Multi-cloud storage spreads data over several providers, but it also multiplies the places where keys, ciphertexts and integrity evidence must be protected. This paper reviews four recent research contributions that approach the problem from complementary angles: hybrid authenticated encryption with sliced storage (CloudLock), publicly verifiable equality testing over encrypted replicas (PVPKEET), blockchain-coordinated, collusion-resistant consistency verification (MDCV), and password-protected key management that survives provider collusion (PECS). We compare their system models, threat assumptions, cryptographic tools, reported costs and limitations, and we outline open issues such as dynamic data support, trusted middleware, and post-quantum readiness.
