A resilient identity-based authenticated key exchange protocol

Abstract

This paper presents a new security notion for key exchange (KE) protocols called resiliency. That is, if a shared secret between a group of parties is compromised or leaked, they can generate another completely new shared secret without the need to set up a new KE session. We present an identity‐based authenticated KE protocol that satisfies the resiliency security property. We prove that if an l‐bit shared secret key (SSK) is leaked, then two parties P1 and P2 can safely generate another shared secret SSK1 without the need to establish a new session. We adjust the unauthenticated adversarial model of the Canetti–Krawczyk to meet this security property and prove the security of the proposed protocol using the Canetti–Krawczyk model based on the quadratic residuosity assumption. Copyright © 2015 John Wiley & Sons, Ltd.

Cryptanalysis of an identity‐based authenticated key exchange protocol

“…In this paper, we have studied the security of the IBAKE protocol in introduced in [7]. The authors claimed that their protocol is provably secure when during the key exchange session some secret bits are leaked.…”

“…For more details we refer the reader to [3]. Finally we state an important lemma that shows an important property used in [3] and [7].…”

“…ELASHRY-MU-SUSILO (EMS) IBAKE SCHEME EMS scheme [7] is specified by the following algorithms ( Fig. 1): (1) (msk, mpk) ← Setup(λ).…”

“…In Section 3, we present EMS IBAKE protocol. 11 In Section 4, we describe our attacks against this protocol. In Section 5, we discuss the question of repairing the scheme.…”

“…This work was then followed by several works. Recently, Elashry, Mu and Susilo [7] proposed another IBAKE protocol and introduced a new security notion called resiliency. A key exchange protocol is said to be resilient when parties are able to generate new shared secret keys without establishing a new session between them, even if a secret shared key has been compromised.…”