This paper proposes a scheme to provide security to dynamic multicast VoIP systems efficiently. Security is usually provided by encrypting the media packets sent from a user to other users with the help of a shared key called the session encryption key. The most time consuming process in a dynamic multicast VoIP environment is the group key management. Whenever there is a change in the group me...

We present quantum key distribution schemes which are autocompensating (require no alignment) and symmetric (Alice and Bob receive photons from a central source) for both polarization and timebin qubits. The primary benefit of the symmetric configuration is that both Alice and Bob may have passive setups (neither Alice nor Bob is required to make active changes for each run of the protocol). We...

Most of the symmetric key authentication schemes deployed today are based on principles introduced by Needham and Schroeder [17] more than twenty years ago. However, since then, the computing environment has evolved from a LAN-based client-server world to include new paradigms, including wide area networks, peer-to-peer networks, mobile ad-hoc networks and ubiquitous computing. Also, there are ...

Chaos theory is the study of dynamical systems that are highly sensitive to initial conditions and exhibit seemingly random behavior. From the perspective of cryptography and information security, randomness generated from entirely deterministic systems is a very appealing property. As such, the application of chaos in modern cryptography has been a topic of much research and debate for over a ...

Most of the symmetric key authentication schemes deployed today are based on principles introduced by Needham and Schroeder [14] more than twenty years ago. However, since then, the computing environment has evolved from a LAN-based client-server world to include new paradigms, including wide area networks, peer-to-peer networks, mobile ad-hoc networks and ubiquitous computing. Also, there are ...

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...

Onion routing protocols achieve low-latency anonymous communication on public networks. Up to date, many onion routing protocols have been proposed, such as Tor network, in order to implement the anonymous network connection in the public networks. Although the previous schemes’ multi-pass cryptographic circuit construction appears satisfactory, their circuit construction protocols have some dr...