Paper 2015/483 Original: eprint.iacr.org/2015/483 ↗

Improved security proofs in lattice-based cryptography: using the Rényi divergence rather than the statistical distance

Shi Bai
Adeline Langlois
Tancrëde Lepoint
Amin Sakzad
Damien Stehle
Ron Steinfeld
Abstract

The Rényi divergence is a measure of closeness of two probability distributions. We show that it can often be used as an alternative to the statistical distance in security proofs for lattice-based cryptography. Using the Rényi divergence is particularly suited for security proofs of primitives in which the attacker is required to solve a search problem (e.g., forging a signature). We show that it may also be used in the case of distinguishing problems (e.g., semantic security of encryption schemes), when they enjoy a public sampleability property. The techniques lead to security proofs for schemes with smaller parameters, and sometimes to simpler security proofs than the existing ones.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
History
2018-02-25: last updated
2015-05-21: published
Short URL
https://ia.cr/2015/483
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2015/483,
      author = {Shi Bai and Adeline Langlois and Tancrëde Lepoint and Amin Sakzad and Damien Stehle and Ron Steinfeld},
      title = {Improved security proofs in lattice-based cryptography: using the Rényi divergence rather than the statistical distance},
      howpublished = {Cryptology {ePrint} Archive, Paper 2015/483},
      year = {2015},
      url = {https://eprint.iacr.org/2015/483}
}
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