One Digit Checksum for Data Integrity Verification of Cloud-executed Homomorphic Encryption Operations
Khaled Chait, Mostefa Kara, Abdelkader Laouid, Mohammad Hammoudeh, Ahcène Bounceur
Abstract
Homomorphic encryption is used in many fields, including information storage, data protection, privacy preservation, blockchain, and authentication. This kind of encryption allows an untrusted third party to perform algebraic operations on encrypted data. Protecting the homomorphically encrypted data against accidental or malicious tampering attacks is still an open research challenge. In this paper, we introduce a lightweight technique that allows a data owner to verify the integrity of homomorphically encrypted results performed in the cloud. The proposed method is quick, simple, and applicable, as it depends on adding a single digit to the encrypted message before storing it in the cloud. This digit represents verification proof and is used later to ensure verifiable homomorphic encryption. Our technique can be integrated with any homomorphic scheme that uses encryption with non-isolated plaintext.