We propose an new one-round implicitly authenticated three-party protocol that extends Joux’s protocol as well as a two-party identity-based protocol. Our protocols have a single communication round that consists of ephemeral (one-time) public keys along with certificates in the tripartite protocol, and identities in the identity-based setting. As such our protocols are communication efficient ...

We analyze number agreement in English in the version of Situation Semantics I put forth in [1]. We propose two theoretical notions, agreement target situations and relevance of situations. We propose that structural constraints shift the former in a way governed by the latter. Our analysis shows that number agreement reflects our knowledge about the structure of the world and the speaker's int...

Key agreement protocols are essential for secure communications in open and distributed environments. Recently, identity-based key agreement protocols have been increasingly researched because of the simplicity of public key management. The basic idea behind an identity-based cryptosystem is that a public key is the identity (an arbitrary string) of a user, and the corresponding private key is ...

We propose a generic modelling technique that can be used to extend existing frameworks for theoretical security analysis in order to capture the use of timestamps. We apply this technique to two of the most popular models adopted in literature (Bellare-Rogaway and Canetti-Krawczyk). We analyse previous results obtained using these models in light of the proposed extensions, and demonstrate the...

We present an authentication and key agreement protocol to secure Voice over IP call establishment between interconnection proxies of different domains. The protocol operates on a transaction basis. Each transaction is defined as the set of operations and data required to send an authenticated message from a sender to a responder. A transaction allows a sender to either transmit a cryptographic...

The fifth generation wireless system (5G) is expected to handle an unpredictable number of heterogeneous connected devices and to guarantee at least the same level of security provided by the contemporary wireless standards, including the Authentication and Key Agreement (AKA) protocol. The current AKA protocol has not been designed to efficiently support a very large number of devices. Hence, ...

The A-GDH.2 and SA-GDH.2 authenticated group key agreement protocols showed to be flawed in 2001. Even though the corresponding attacks (or some variants of them) have been rediscovered in several different frameworks, no fixed version of these protocols has been proposed until now. In this paper, we prove that it is in fact impossible to design a scalable authenticated group key agreement prot...

Recently, Isalam and Biswas proposed a new group key agreement (GKA) protocol for imbalanced mobile networks. In this letter, we will show that Isalam et al.’s GKA protocol is not secure.

A secret key agreement framework between three users is considered in which each of the users 1 and 2 intends to share a secret key with user 3 and users 1 and 2 are eavesdroppers with respect to each other. There is a generalized discrete memoryless multiple access channel (GDMMAC) from users 1 and 2 to user 3 where the three users receive outputs from the channel. Furthermore, there is a broa...

UMTS is the most popular third-generation mobile phone system at present, and the UMTS AKA is his authentication and key agreement protocol. There are some weaknesses in the existed UMTS AKA protocol, such as synchronization question, storage overhead, insecurity with leakiness authentication vector, and weakness in mutual authentications. In this paper, we use the concept of proxy key to desig...