Paper 2017/066

Subring Homomorphic Encryption

Seiko Arita and Sari Handa


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.

Note: editorial modifications

Available format(s)
Public-key cryptography
Publication info
Preprint. MINOR revision.
Contact author(s)
arita @ iisec ac jp
2017-06-07: last of 2 revisions
2017-01-31: received
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      author = {Seiko Arita and Sari Handa},
      title = {Subring Homomorphic Encryption},
      howpublished = {Cryptology ePrint Archive, Paper 2017/066},
      year = {2017},
      note = {\url{}},
      url = {}
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