Low-Complexity Computations on Encrypted Data for Fully Homomorphic Encryption

Abstract

Fully homomorphic encryption (FHE) allows computations to be performed directly on encrypted data This ensures data privacy even on the cloud Currently used computations on encrypted data are of extremely high complexity In this paper we propose low-complexity low-level operations on fully homomorphic encrypted data such as compare-and-swap binary addition and binary multiplication To improve the algorithmic performance we apply the concept of aggregate plaintext The number of homomorphic multiplications in our compare-and-swap binary addition and binary multiplication are lg n+4 2n-1 and 6n-4 respectively For 64-bit data compare-and-swap and binary addition the proposed algorithms operate over 16 and 9 times faster than related works respectively For 32-bit multiplication the speed improvement is over 7 times

Date of Award	2019
Original language	English
Supervisor	Ming-Der Shieh (Supervisor)