Ruminations on Fully Homomorphic Encryption in Client-server Computing Scenario

Zhengjun Cao ； Lihua Liu ； Yang Li

《International Journal of Electronics and Information Engineering》 8卷1期 (2018/03) Pp. 32-39

https://doi.org/10.6636/IJEIE.201803.8(1).04

摘要

Fully homomorphic encryption (FHE) allows anyone to perform computations on encrypted data, despite not having the secret decryption key. Since the Gentry's work in 2009, FHE has become a hot topic. In this paper, we would like to stress that any computations performed on encrypted data are constrained intrinsically to the underlying domain (finite fields or rings). This restriction makes the primitive useless for the computations involving common arithmetic expressions and relational expressions, because of the incompatibility of numerical computation with underlying encoding transformation over finite domains. We want to reaffirm that cryptography uses modular arithmetic a lot in order to obscure and dissipate redundancies in plaintext, not to perform any numerical calculations. Thus FHE will be of little importance to client-server computing or cloud computing.

關鍵字

Client-server Computing ； Common Arithmetic ； Encryption Domain ； Fully Homomorphic Encryption ； Modular Arithmetic