## Cryptology ePrint Archive: Report 2017/066

Subring Homomorphic Encryption

Seiko Arita and Sari Handa

Abstract: In this paper, we construct {\em subring homomorphic encryption} scheme that is a homomorphic encryption scheme build on the decomposition ring, which is a subring of cyclotomic ring. In the scheme, each plaintext slot contains an integer in $\mathbb{Z}_{p^l}$, rather than an element of $\mathrm{GF}(p^d)$ as in conventional homomorphic encryption schemes on cyclotomic rings. Our benchmark results indicate that the subring homomorphic encryption scheme is several times faster than HElib {\em for mod-$p^l$ plaintexts}, due to its high parallelism of mod-$p^l$ slot structure. We believe in that the plaintext structure composed of mod-$p^l$ slots will be more natural, easy to handle, and significantly more efficient for many applications such as outsourced data mining.

Category / Keywords: public-key cryptography /

Date: received 31 Jan 2017, last revised 7 Jun 2017

Contact author: arita at iisec ac jp

Available format(s): PDF | BibTeX Citation

Note: editorial modifications

Short URL: ia.cr/2017/066

[ Cryptology ePrint archive ]