Abstract
For secure remote processing, homomorphic encryption can be used. It allows operations to be performed on encrypted data. If the processor needs the result’s plaintext, it relies on the data owner to perform the decryption. This poses a vulnerability since a malicious data owner could inject a self–selected value. Moreover, it sees the plaintext result, breaching its confidentiality. In this paper, we propose a solving approach for the CKKS homomorphic encryption scheme. Using a commutative property, the data owner removes its encryption, while a processor’s encryption reinforces integrity and confidentiality. In an evaluation, we demonstrate feasibility regarding computational effort, transmitted data size, and introduced error.