Some platforms allow multiple tenants to share the same infrastructure, which is the basis of multi-tenancy, providing scalability and cost efficiency. But it brings with it significant security challenges, specifically around data isolation, confidentiality and integrity. Encryption acts as a solution for these problems by keeping critical tenant information safe. This research examines the impact of a multi-tenant cloud architecture in terms of encryption approaches adopted, their respective advantages and disadvantages, and how they can be applied to address various security challenges.We evaluate key encryption methods like RSA, AES, and ECC that help secure data storage, control encryption keys, and ensure data isolation among tenants. Further, it discusses the possible integration of encryption with blockchain technology as a means for counterbalancing security threats on shared cloud networks. Performance metrics like scalability, resource utilization and latency are then analyzed to provide a holistic perspective on the evaluation. Although encryption methods are well established to defend data in this manner, they are not infallible. Thus, in this study the authors have recognized the points required for additional optimization in existing encryption process and have introduced an optimized encryption architecture which has combined 3 prominent algorithms to provide significant security to the multi- tenant cloud with RSA, AES & ECC respectively.