Anonymous and Transparent Gateway-based Password-Authenticated Key Exchange

The original publication is available at www.springerlink.comInternational audienceIn Asiacrypt 2005, Abdalla et al. put forward the notion of gateway-based password- authenticated key exchange (GPAKE) protocol, which allows clients and gateways to establish a common session key with the help of an authentication server. In addition to the semantic security of the session key, their solution also provided additional security properties such as password pro- tection with respect to malicious gateways and key privacy with respect to curious authentication servers. In this paper, we further pursue this line of research and present a new and stronger se- curity model for GPAKE schemes, combining all above-mentioned security properties. In addition to allowing a security proof for all these security properties, the new security model has also other advantages over the previous one such as taking into account user corruptions. After describing the new security model, we then present a new variant of the GPAKE scheme of Abdalla et al. with similar efficiency. Like the original scheme, the new scheme is also transparent in that it does not differ significantly from a classical 2-PAKE scheme from the point of view of a client. Finally, we also show how to add client anonymity with respect to the server to the basic GPAKE scheme by using private information retrieval protocols

Authentic-caller : self-enforcing authentication in a next generation network

The Internet of Things (IoT) or the Cyber-Physical System (CPS) is the network of connected devices, things and people which collect and exchange information using the emerging telecommunication networks (4G, 5G IP-based LTE). These emerging telecommunication networks can also be used to transfer critical information between the source and destination, informing the control system about the outage in the electrical grid, or providing information about the emergency at the national express highway. This sensitive information requires authorization and authentication of source and destination involved in the communication. To protect the network from unauthorized access and to provide authentication, the telecommunication operators have to adopt the mechanism for seamless verification and authorization of parties involved in the communication. Currently, the next-generation telecommunication networks use a digest-based authentication mechanism, where the call-processing engine of the telecommunication operator initiates the challenge to the request-initiating client or caller, which is being solved by the client to prove his credentials. However, the digest-based authentication mechanisms are vulnerable to many forms of known attacks e.g., the Man-In-The-Middle (MITM) attack and the password guessing attack. Furthermore, the digest-based systems require extensive processing overheads. Several Public-Key Infrastructure (PKI) based and identity-based schemes have been proposed for the authentication and key agreements. However, these schemes generally require smart-card to hold long-term private keys and authentication credentials. In this paper, we propose a novel self-enforcing authentication protocol for the SIPbased next-generation network based on a low-entropy shared password without relying on any PKI or trusted third party system. The proposed system shows effective resistance against various attacks e.g., MITM, replay attack, password guessing attack, etc. We a..