In this paper, we analyze the security of a group key establishment scheme proposed by López-Ramos et al. This proposal aims at allowing users to agree on common key. We present several attacks against protocol. particular, an active attack is presented, and it also proved that protocol does not provide forward secrecy.

Modern multi-user communication systems, including popular instant messaging tools, social network platforms, and cooperative-work applications, offer flexible forms of communication and exchange of data. At any time point concurrent communication sessions involving different subsets of users can be invoked. The traditional tool for achieving security in a multi-party communication environment ...

Confidentiality, integrity and authentication are more relevant issues in Ad hoc networks than in wired fixed networks. One way to address these issues is the use of symmetric key cryptography, relying on a secret key shared by all members of the network. But establishing and maintaining such a key (also called the session key) is a non-trivial problem. We show that Group Key Agreement (GKA) pr...

When a sensor network is deployed in a hostile environment, an adversary may launch such attacks as eavesdropping the communications and compromising sensor nodes. Using the compromised nodes, he may inject false sensing reports or modify the reports sent by other nodes. To defend against these attacks, researchers have proposed symmetric group key-based schemes. In these schemes, however, if a...