R. Srinivasan

Secure Group Key Management Scheme for Multicast Networks

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 membership, the key needs to be updated and the updated key has to be sent to all active members in the group. Hence, by decreasing the number of update messages required for an updated key, the performance of the system can be improved considerably, thus making the scheme more efficient. The proposed secure multicast key management scheme combines the advantages of logical-key tree structure and Chinese remainder theorem to achieve an effective scheme. This paper compares the efficiency of the proposed scheme with the existing schemes and the comparison shows that the proposed scheme performs better than the existing schemes in terms of reduction in key update messages.

Authentication of Signaling in VoIP Applications

Session initiation protocol known as SIP is currently being preferred to H.323 protocol due to its simple architecture. In traditional SIP, security mechanisms are inadequate for assuring the identity of the end user based on cryptography. This is vulnerable in the sense that a third person, an impersonator, may easily duplicate one of the users engaged in the session. This can pose serious threats as it affects the secrecy of the user. In order to reduce the threat posed by an eavesdropper, an authentication scheme is required. This paper proposes a scheme for authenticating the end users identities with the outbound proxy server in that domain with the help of the registrar server. The authentication scheme is based on end users public key infrastructure (PKI) certificate and strong one way hash function. The proposed scheme is implemented using JAVA and tested for its validity in a LAN environment. The delay overhead in providing authentication in the proposed scheme is found to be within the allowable limit as per IETF standard

Transmembrane START domain proteins: in silico identification, characterization and expression analysis under stress conditions in chickpea (Cicer arietinum L.)

Steroidogenic acute regulatory related transfer (StART) proteins that are involved in transport of lipid molecules, play a myriad of functions in insects, mammals and plants. These proteins consist of a modular START domain of approximately 200 amino acids which binds and transfers the lipids. In the present study we have performed a genome-wide search for all START domain proteins in chickpea. The search identified 36 chickpea genes belonging to the START domain family. Through a phylogenetic tree reconstructed with Arabidopsis, rice, chickpea, and soybean START proteins, we were able to identify four transmembrane START (TM-START) proteins in chickpea. These four proteins are homologous to the highly conserved mammalian phosphatidylcholine transfer proteins. Multiple sequence alignment of all the transmembrane containing START proteins from Arabidopsis, rice, chickpea, and soybean revealed that the amino acid residues to which phosphatidylcholine binds in mammals, is also conserved in all these plant species, implying an important functional role and a very similar mode of action of all these proteins across dicots and monocots. This study characterizes a few of the not so well studied transmembrane START superfamily genes that may be involved in stress signaling. Expression analysis in various tissues showed that these genes are predominantly expressed in flowers and roots of chickpea. Three of the chickpea TM-START genes showed induced expression in response to drought, salt, wound and heat stress, suggesting their role in stress response.

Multi-path routing scheme for non-interactive multicast communications

This paper proposes a multicast routing algorithm that makes use of multiple node-disjoint distribution trees for its routing from the source to the multicast group members. The specialty of this scheme is that the different packets of a message between a source and destinations are routed through node-disjoint paths to provide reliable and secure multicast communication. In this proposed routing scheme the computation of the node disjoint path for packet routing is done either at a centralized route moderator or in a distributed fashion at all destinations in order to avoid single point failure. An effective provision is made to enable new member join to the existing multicast trees and to prune leaving members. The performance parameters of the proposed reliable and secure multi path routing scheme are studied under various network conditions using GloMoSim.

Modeling of Various Phases of Micro Satellite using Timed Petri Nets

The modeling of various working phases of a satellite system is a challenging task. Petri nets are powerful tool for modeling systems. For more than a decade, the satellite missions have been using micro satellites in low earth orbits. These micro satellites could be used to test advanced technologies for future operational satellites ANUSAT is a low earth orbit micro satellite. The primary payload of ANUSAT is the store and forward payload. The main application of store and forward payload is to support communication between clients in various footprints of the satellite. This paper is about the modeling of various working phases of ANUSAT using Petri nets based on time

Multi-Path Routing Scheme for Non-Interactive Multicast Communications

This paper proposes a multicast routing algorithm that makes use of multiple node-disjoint distribution trees for its routing from the source to the multicast group members. The specialty of this scheme is that the different packets of a message between a source and destinations are routed through node-disjoint paths to provide reliable and secure multicast communication. In this proposed routing scheme the computation of the node disjoint path for packet routing is done either at a centralized route moderator or in a distributed fashion at all destinations in order to avoid single point failure. An effective provision is made to enable new member join to the existing multicast trees and to prune leaving members. The performance parameters of the proposed reliable and secure multi path routing scheme are studied under various network conditions using GloMoSim.