Cryptographic protocols are designed to provide security services, such as key distribution, authentication and non-repudiation, over insecure networks. The design process of cryptographic protocols is highly complex. In particular, the translation from the informal protocol description to the formal protocol specification is an error-prone step, as the exact meaning of the requirements of the ...

As mobile devices pervade physical space, the familiar authentication patterns are becoming insufficient: besides entity authentication, many applications require, e.g. location authentication. While many interesting and subtle protocols have been proposed and implemented to provide such strengthened authentication, there are very few proofs that such protocols satisfy the required properties. ...

Most of the password based authentication protocols make use of the single authentication server for user’s authentication. User’s verifier information stored on the single server is a main point of susceptibility and remains an attractive target for the attacker. On the other hand, multi-server architecture based authentication protocols make it difficult for the attacker to find out any signi...

In the context of Dolev-Yao style analysis of security protocols, we investigate the security claims of a proposed strong-security RFID authentication protocol. We exhibit a flaw which has gone unnoticed in RFID protocol literature and present the resulting attacks on authentication, untraceability, and desynchronization resistance. We analyze and discuss the authors’ proofs of security. Refere...

There is still no consistent definition of general ad hoc network properties. All introduced protocols for ad hoc networks are based on different assumptions and security requirements, and are consequently suited for specific applications only. Due to the broad field of applications, a general security model can still not be found in any literature. We define two ad hoc network categories, name...

A secure peer-to-peer communication over an insecure channel without any prior exchanged key can be established with the help of an authentication step to exchange a public key. Then, standard methods of public-key cryptography such as RSA can be used to communicate securely. In this work, we concentrate on message authentication protocols which require an extra authenticated channel. We start ...

Authentication protocols are very simple distributed algorithms whose purpose is to enable two entities to achieve mutual and reliable agreement on some piece of information, typically the identity of the other party, its presence, the origin of a message, its intended destination. Achieving the intended agreement guarantees is subtle because they typically are the result of the encryption/decr...

Authentication based on cryptographic protocols is a key technology for recent security systems. However, the so-called relay attack where a malicious attacker tries to assume the role of the prover, is known to be a serious threat even for the cryptographically-secure authentication systems. This paper proposes a new authentication method that utilizes the side channel that already exists in m...