Verifiable Homomorphic Encrypted Computations for Cloud Computing

Abstract

Cloud computing is becoming an essential part of computing, especially for enterprises. As the need for cloud computing increases, the need for cloud data privacy, con-fidentially, and integrity are also becoming essential. Among potential solutions, homomorphic encryption can provide the needed privacy and confidentiality. Unlike traditional cryptosys-tem, homomorphic encryption allows computation delegation to the cloud provider while the data is in its encrypted form. Unfortunately, the solution is still lacking in data integrity. While on the cloud, there is a possibility that valid homomorphically encrypted data beings swapped with other valid homomorphically encrypted data. This paper proposes a verification scheme based on the modular residue to validate homomorphic encryption computation over integer finite field to be used in cloud computing so that data confidentiality, privacy, and data integrity can be en-forced during an outsourced computation. The performance of the proposed scheme varied based on the underlying cryptosystems used. However, based on the tested cryptosystems, the scheme has 1.5% storage overhead and a computational overhead that can be configured to work below 1%. Such overhead is an acceptable trade-off for verifying cloud computation which is highly needed in cloud computing.