Paper 2018/453 Original: eprint.iacr.org/2018/453 ↗
Floppy-Sized Group Signatures from Lattices
Abstract
We present the first lattice-based group signature scheme whose cryptographic artifacts are of size small enough to be usable in practice: for a group of $2^{25}$ users, signatures take 910 kB and public keys are 501 kB. Our scheme builds upon two recently proposed lattice-based primitives: the verifiable encryption scheme by Lyubashevsky and Neven (Eurocrypt 2017) and the signature scheme by Boschini, Camenisch, and Neven (IACR ePrint 2017). To achieve such short signatures and keys, we first re-define verifiable encryption to allow one to encrypt a function of the witness, rather than the full witness. This definition enables more efficient realizations of verifiable encryption and is of independent interest. Second, to minimize the size of the signatures and public keys of our group signature scheme, we revisit the proof of knowledge of a signature and the proofs in the verifiable encryption scheme provided in the respective papers.
Metadata
- Available format(s)
PDF- Category
- Public-key cryptography
- Publication info
- Preprint.
- History
- 2019-06-28: last updated
- 2018-05-21: published
- Short URL
- https://ia.cr/2018/453
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2018/453,
author = {Cecilia Boschini and Jan Camenisch and Gregory Neven},
title = {Floppy-Sized Group Signatures from Lattices},
howpublished = {Cryptology {ePrint} Archive, Paper 2018/453},
year = {2018},
url = {https://eprint.iacr.org/2018/453}
}