δ-subgaussian Random Variables in Cryptography

Sean Murphy; Rachel Player

Paper 2017/698

δ-subgaussian Random Variables in Cryptography

Sean Murphy and Rachel Player

Abstract

In the Ring-LWE literature, there are several works that use a statistical framework based on delta-subgaussian random variables. These were introduced by Miccancio and Peikert (Eurocrypt 2012) as a relaxation of subgaussian random variables. In this paper, we completely characterise delta-subgaussian random variables. In particular, we show that this relaxation from a subgaussian random variable corresponds only to the shifting of the mean. Next, we give an alternative noncentral formulation for a delta-subgaussian random variable, which we argue is more statistically natural. This formulation enables us to extend prior results on sums of delta-subgaussian random variables, and on their discretisation.

Metadata

Available format(s): PDF
Publication info: Published elsewhere. ACISP 2019 : The 24th Australasian Conference on Information Security and Privacy
Keywords: Ring Learning with Errors Subgaussian Random Variable.
Contact author(s): s murphy @ rhul ac uk
History: 2019-04-04: last of 4 revisions; 2017-07-21: received; See all versions
Short URL: https://ia.cr/2017/698
License: CC BY

BibTeX

@misc{cryptoeprint:2017/698,
      author = {Sean Murphy and Rachel Player},
      title = {δ-subgaussian Random Variables in Cryptography},
      howpublished = {Cryptology {ePrint} Archive, Paper 2017/698},
      year = {2017},
      url = {https://eprint.iacr.org/2017/698}
}