One Round Group Key Exchange with Forward Security in the Standard Model

M.  Choudary Gorantla; Colin Boyd; Juan Manuel González Nieto

Paper 2010/083

One Round Group Key Exchange with Forward Security in the Standard Model

M. Choudary Gorantla, Colin Boyd, and Juan Manuel González Nieto

Abstract

Constructing a one round group key exchange (GKE) protocol that provides forward secrecy is an open problem in the literature. In this paper, we investigate whether or not the security of one round GKE protocols can be enhanced with any form of forward secrecy without increasing the number of rounds. We apply the {\em key evolving} approach used for forward secure encryption/signature schemes and then model the notion of forward security for the first time for key exchange protocols. This notion is slightly weaker than forward secrecy, considered traditionally for key exchange protocols. We then revise an existing one round GKE protocol to propose a GKE protocol with forward security. In the security proof of the revised protocol we completely avoid reliance on the random oracle assumption that was needed for the proof of the base protocol. Our security proof can be directly applied to the base protocol, making it the most efficient one round GKE protocol secure in the standard model. Our one round GKE protocol is generically constructed from the primitive of forward secure encryption. We also propose a concrete forward secure encryption scheme with constant size ciphertext that can be used to efficiently instantiate our protocol.

Metadata

Available format(s): PDF PS
Category: Cryptographic protocols
Publication info: Published elsewhere. Unknown where it was published
Keywords: group key exchange forward security key evolving standard model
Contact author(s): mc gorantla @ isi qut edu au
History: 2010-02-22: received
Short URL: https://ia.cr/2010/083
License: CC BY

BibTeX

@misc{cryptoeprint:2010/083,
      author = {M.  Choudary Gorantla and Colin Boyd and Juan Manuel González Nieto},
      title = {One Round Group Key Exchange with Forward Security in the Standard Model},
      howpublished = {Cryptology ePrint Archive, Paper 2010/083},
      year = {2010},
      note = {\url{https://eprint.iacr.org/2010/083}},
      url = {https://eprint.iacr.org/2010/083}
}