On-Line/Off-Line DCR-based Homomorphic Encryption and Applications

Marc Joye

Paper 2023/048

On-Line/Off-Line DCR-based Homomorphic Encryption and Applications

Marc Joye

, Zama

Abstract

On-line/off-line encryption schemes enable the fast encryption of a message from a pre-computed coupon. The paradigm was put forward in the case of digital signatures. This work introduces a compact public-key additively homomorphic encryption scheme. The scheme is semantically secure under the decisional composite residuosity (DCR) assumption. Compared to Paillier cryptosystem, it merely requires one or two integer additions in the on-line phase and no increase in the ciphertext size. This work also introduces a compact on-line/off-line trapdoor commitment scheme featuring the same fast on-line phase. Finally, applications to chameleon signatures are presented.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Published elsewhere. CT-RSA 2023
DOI: 10.1007/978-3-031-30872-7_5
Keywords: On-line/off-line encryption Additively homomorphic encryption Trapdoor commitments Chameleon signatures
Contact author(s): marc @ zama ai
History: 2023-04-27: revised; 2023-01-16: received; See all versions
Short URL: https://ia.cr/2023/048
License: CC BY

BibTeX

@misc{cryptoeprint:2023/048,
      author = {Marc Joye},
      title = {On-Line/Off-Line {DCR}-based Homomorphic Encryption and Applications},
      howpublished = {Cryptology {ePrint} Archive, Paper 2023/048},
      year = {2023},
      doi = {10.1007/978-3-031-30872-7_5},
      url = {https://eprint.iacr.org/2023/048}
}