Minimizing Ciphertext in Homomorphic Encryption Scheme for Cloud Data

Data security is a major concern in cloud computing. It must satisfy the three goals of security in computing-integrity, confidentiality, and availability. Homomorphic encryption is a technique in which user or cloud service provider (CSP) can perform operations on cloud data without performing decryption. Many algorithms are available for homomorphic encryption. But these algorithms generate large size ciphertext. This paper focuses on homomorphic encryption which generates small size ciphertext. It is a variant of scheme proposed by Dijk et al. In an experimentation of this scheme, encrypted data are stored in DynamoDB of Amazon Web service (AWS) public cloud. When user requires data, it can be downloaded on users machine and then decrypted.