We describe a cryptanalysis of the GGH15 multilinear maps. Our attack breaks the multipartite key-agreement protocol in polynomial time by generating an equivalent user private key; it also applies to GGH15 with safeguards. We also describe attacks against variants of the GGH13 multilinear maps proposed by Halevi (ePrint 2015/866) aiming at supporting graph-induced constraints, as in GGH15.

The Algebraic Eraser (AE) is a public key protocol for sharing information over an insecure channel using commutative and noncommutative groups; a concrete realization is given by Colored Burau Key Agreement Protocol (CBKAP). In this paper, we describe how to choose data in CBKAP to thwart an attack by Kalka–Teicher–Tsaban.

Traditional password based authentication schemes are mostly considered in single server environments. They are unfitted for the multi-server environments from two aspects. On the one hand, users need to register in each server and to store large sets of data, including identities and passwords. On the other hand, servers are required to store a verification table containing user identities and...

Next generation networks will comprise different wireless networks including cellular technologies, WLAN and indoor technologies. To support these heterogeneous environments, there is a need to consider a new design of the network infrastructure. Furthermore, this heterogeneous environment implies that future devices will need to roam between different networks using vertical handover technique...

We give interpretations of some known key agreement protocols in the framework of category theory and in this way we give a method of constructing of many new key agreement protocols.

We present a new two-party attribute-based key agreement protocol that is secure without the random oracle model in groups equipped with a bilinear map. The attribute-based key agreement scheme is one type of the identity-based key agreement scheme, in which the identity can be viewed as a set of descriptive attributes. These kinds of schemes provide some new properties, such as hiding the iden...

User mobility is a feature that raises many issues related to security. One of them is the disclosure of a mobile user's real identity during the authentication process, or the other procedures specific to global mobile networks (GLOMONET). Such disclosure allows an unauthorized third-party to track the mobile user's movements and current whereabouts. In this article, we address some problems o...

Identity-based cryptography has become extremely fashionable in the last few years. As a consequence many proposals for identitybased key establishment have emerged, the majority in the two party case. We survey the currently proposed protocols of this type, examining their security and efficiency. Problems with some published protocols are noted.

The method of key sharing between a mobile unit and a base station through a wirelessMIMO-based fading channel is investigated. The expressions to estimate the correct keybit agreement based on a quantization with the use of guard interval are proved. Thegenerated key sequences are tested on pseudo randomness and improved by applicationof some transforms. It provides that these key sequences pa...

Group Key Agreement (GKA) protocols enable the participants to derive a key based on each one’s contribution over a public network without any central authority. They also provide efficient ways to change the key when the participants change. While some of the proposed GKA protocols are too resource consuming for the constraint devices often present in ad hoc networks, others lack a formal secu...