Towards KEM Unification

Daniel J.  Bernstein; Edoardo Persichetti

Paper 2018/526

Towards KEM Unification

Daniel J. Bernstein and Edoardo Persichetti

Abstract

This paper highlights a particular construction of a correct KEM without failures and without ciphertext expansion from any correct deterministic PKE, and presents a simple tight proof of ROM IND-CCA2 security for the KEM assuming merely OW-CPA security for the PKE. Compared to previous proofs, this proof is simpler, and is also factored into smaller pieces that can be audited independently. In particular, this paper introduces the notion of ``IND-Hash'' security and shows that this allows a new separation between checking encryptions and randomizing decapsulations. The KEM is easy to implement in constant time, given a constant-time implementation of the PKE.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint. MINOR revision.
Keywords: PKE OW-CPA OW-Passive IND-Hash rigid KEM IND-CCA2 ROM
Contact author(s): authorcontact-tightkem @ box cr yp to
History: 2018-06-04: received
Short URL: https://ia.cr/2018/526
License: CC BY

BibTeX

@misc{cryptoeprint:2018/526,
      author = {Daniel J.  Bernstein and Edoardo Persichetti},
      title = {Towards {KEM} Unification},
      howpublished = {Cryptology {ePrint} Archive, Paper 2018/526},
      year = {2018},
      url = {https://eprint.iacr.org/2018/526}
}