V. Sumathy

Efficient Region -Based Group Key Agreement Protocol for Ad Hoc Networks using Elliptic Curve Cryptography

A Group Key Agreement (GKA) protocol is a mechanism to establish a cryptographic key for a group of participants, based on each ones contribution, over a public network. Security of various group-oriented applications for ad-hoc groups requires a group secret shared between all participants. In ad hoc networks, the movement of the network nodes may quickly change the topology resulting in the increased in e overhead during messaging for topology maintenance, the region based schemes of ad hoc networks therefore aim at handling topology maintenance, managing node movement and reducing overhead. When the group composition changes, group controller can employ supplementary GKA protocols to derive a new key. Thus, they are well-suited to the key establishment needs of dynamic peer-to-peer networks as in ad hoc networks. While many of the proposed GKA protocols are too expensive to be employed by the constrained devices often present in ad hoc networks, others lack a formal security analysis. In this paper, a simple, secure and efficient Region Based GKA protocol using Elliptic Curve Cryptography well suited to dynamic ad hoc networks is presented. This paper introduces a Region-Based contributory group key agreement that achieves the performance lower bound by utilizing a novel Group Elliptic Curve Diffie-Hellman (GECDH) protocol and Tree-based Group Elliptic Curve Diffle-Hellman (TGECDH) protocol, called GEDH & TGECDH protocol. Both theoretical and simulation studies shows that the proposed scheme achieves much lower communication, computation and memory cost than the existing Group Diffie-Hellman and Tree based contributory group key agreement schemes.

A survey of seamless vertical handoff schemes for Wi-Fi/WiMAX heterogeneous networks

One of the most important issues in wireless and mobile communication technologies is to provide seamless handoff when a mobile node(MN) moves between different access networks. In this paper we have taken Wi-Fi/WiMAX heterogeneous networks in to consideration and reviewed the various seamless handoff schemes for vertical handoff between Wi-Fi and WiMAX networks at different layers. We assume the mobile terminals in our proposed network support IEEE 802.11 and IEEE802.16e dual interface. And also we have compared the schemes based on different criteria viz., handoff latency, packet loss, to provide a better QoS in real-time user scenarios. The comparison reveals the pros and cons of each scheme and aids to adopt a better scheme to achieve seamless handoff in next generation wireless networks.

Performance analysis of a context aware cross layer scheme for fast handoff in IMS based integrated WiFi-WiMax networks

Providing fast and seamless handoff in a pervasive computing environment is one of the recent research issues. The delay incurred due to IP Multimedia subsystem (IMS) re-registration and session re-setup process during vertical handoff (VHO) is still a major bottleneck for Voice Over IP (VoIP) and interactive multimedia services. In the conventional Session initiation Protocol (SIP), handoff performance is very poor due to high handoff delay and packet loss. In this paper, we propose two SIP based schemes, a Context Awareness (CA)-based Pre-registration approach to reduce the IMS Re-registration delay and a novel scheme called Prior-SIP (P-SIP) with a cross layer scheme utilizing Media Independent Handover (MIH) services to reduce the IMS session re-setup delay in a WiFi/WiMax heterogeneous environment by defining new SIP messages. We have simulated these scenarios using NS2 and the performance characteristics are studied. We have also analyzed the IMS pre-registration delay and IMS session re-setup delay based on Queuing theory. The simulation and analytical results show that, the proposed solution shows an improvement of 44% in terms of handoff delay and packet loss when compared with previous approaches and was able to maintain 90% throughput during handoff and suits well for supporting real-time applications to mobile users.

FPGA implementation of Low Power High Speed square root circuits

We present an efficient methodology for square root calculation using non-restoring SQUARE ROOT algorithm. The main principle of the proposed method is similar with conventional non-restoring algorithm, except that it eliminates the need for previous quotient in its final iteration. To reduce gate count we have proposed two area efficient subtract units and used in our proposed design. As an enhancement to our work we evaluated the design by eliminating the need for calculation of partial remainder in the final iteration. The proposed design and its enhanced version are designed using VHDL and simulated using Synopsys design compiler. Experimental results demonstrates better performance of our proposed architecture compared with the prior art in terms of area, power and delay.

A Swarm Based Defense Technique for Jamming Attacks in Wireless Sensor Networks

Jamming can interrupt wireless transmission and occur by mistake in form of interference, noise or as collision at the receiver or in the circumstance of an attack. In this paper, we propose a swarm based defense technique for jamming attacks in wireless sensor networks. Swarm intelligence algorithm is proficient enough to adapt change in network topology and traffic. The sender and receiver change channels in order to stay away from the jammer, in channel hoping technique. The jammers remain on a single channel, hoping to disrupt any fragment that may be transmitted in the pulse jamming technique. Using the swarm intelligence technique, the forward ants either unicast or broadcast at each node depending on the availability of the channel information for end of the channel. If the channel information is available, the ants randomly choose the next hop. As the backward ants reaches the source, the data collected is verified which channel there is prevalence of attacker long time, and those are omitted. Simultaneously the forward ants are sent through other channels which are not detected before for attacks. This scheme helps limit the channel maintenance overhead. By simulation results, it is clear that this swarm based defense technique for jamming attack is more effective than the existing works.

Multilevel access control in defense messaging system using Elliptic curve cryptography

Instant messaging technology is the primary mechanism for information sharing and has been the force of success of all social networking sites. Taking this clue, government and military organizations have also started using messaging for quick and fast actions. Defense messaging system takes a message and forwards it to the intending recipients or parties based on the message criteria for immediate action. This system should provide security assurance and should be manageable by central administrative authority instead of relying on the individual users. The primary goal of this research is to develop a multilevel access control for Defense messaging system using Elliptic curve cryptography. The system developed is secure, multi site and allows for global communication using the inherent properties of Elliptic Curve cryptography. Elliptic Curve cryptography provides a greater security with less bit size and it is fast when compared to other schemes. The implementation suggests that it is a secure system which occupies fewer bits and can be used for low power devices.

A Novel Approach towards Cost Effective Region-Based Group Key Agreement Protocol for Ad Hoc Networks Using Elliptic Curve Cryptography

This paper addresses an interesting security problem in wireless ad hoc networks: the dynamic group key agreement key establishment. For secure group communication in an ad hoc network, a group key shared by all group members is required. This group key should be updated when there are membership changes (when the new member joins or current member leaves) in the group. In this paper, we propose a novel, secure, scalable and efficient region-based group key agreement protocol for ad hoc networks. This is implemented by a two-level structure and a new scheme of group key update. The idea is to divide the group into subgroups, each maintaining its subgroup keys using group elliptic curve diffie-hellman (GECDH) Protocol and links with other subgroups in a tree structure using tree-based group elliptic curve diffie-hellman (TGECDH) protocol. By introducing region-based approach, messages and key updates will be limited within subgroup and outer group; hence computation load is distributed to many hosts. Both theoretical analysis and experimental results show that this Region-based key agreement protocol performs well for the key establishment problem in ad hoc network in terms of memory cost, computation cost and communication cost.

Design and Implementation of Multilevel Access Control in Synchronized Audio to Audio Steganography Using Symmetric Polynomial Scheme

Steganography techniques are used in Multimedia data transfer to prevent adversaries from eaves dropping. Synchronized audio to audio steganography deals with recording the secret audio, hiding it in another audio file and subsequently sending to multiple receivers. This paper proposes a Multilevel Access control in Synchronized audio steganography, so that Audio files which are meant for the users of low level class can be listened by higher level users, whereas the vice-versa is not allowed. To provide multilevel access control, symmetric polynomial based scheme is used. The steganography scheme makes it possible to hide the audio in different bit locations of host media without inviting suspicion. The Secret file is embedded in a cover media with a key. At the receiving end the key can be derived by all the classes which are higher in the hierarchy using symmetric polynomial and the audio file is played. The system is implemented and found to be secure, fast and scalable. Simulation results show that the system is dynamic in nature and allows any type of hierarchy. The proposed approach is better even during frequent member joins and leaves. The computation cost is reduced as the same algorithm is used for key computation and descendant key derivation. Steganography technique used in this paper does not use the conventional LSB’s and uses two bit positions and the hidden data occurs only from a frame which is dictated by the key that is used. Hence the quality of stego data is improved.

A Novel Approach towards Cost Effective Region-Based Group Key Agreement Protocol for Ad Hoc Networks

A group key agreement (GKA) protocol is a mechanism to establish a cryptographic key for a group of participants, based on each one’s contribution, over a public network. In ad-hoc networks, the movement of the nodes may quickly change the topology resulting in the increased overhead during messaging for topology maintenance. The Region-based schemes of ad-hoc networks, aim of handling topology maintenance, managing node movement and reducing overhead. In this paper, a simple, secure and efficient Region-based GKA protocol using CRTDH&TGDH well suited to dynamic ad-hoc networks is presented and also introduces a region-based contributory group key agreement that achieves the performance lower bound by utilizing a novel CRTDH and TGDH protocol called CRTDH&TGDH protocol. Both theoretical and experimental results show that the proposed scheme achieves communication, computation and memory cost is lower than the existing group key agreement schemes.

Swarm-based defense technique for tampering and cheating attack in WSN using CPHS

Nowadays, Wireless Sensor Networks (WSN) have been seen as one of the most essential technologies which play a vital role in several important areas, such as healthcare, military, critical infrastructure monitoring, environment monitoring, and manufacturing. The desirable nature of WSN introduces many security challenges which have necessitated the introduction of several classical security methodologies over the last few years for various security attacks. A defense technique using Swarm Based Trusted Node for Tampering and Cheating Attack (SBTN-TC) model has been proposed to identify the physical layer attacks in a WSN. This model, first selects a trusted node (TN) within the network for identifying the tampered or cheating nodes using swarm intelligence. The trusted node monitors and processes the nodes session receipts involved in the transmission session to extract the contextual information such as broken links, frequent packet droppers, and fair and cheating sessions. Based on the session receipts, the trusted node renews the nodes certificate and ignores the tampered node or cheating node. In order to maintain a secure communication of contextual information between node and trusted node, a Cryptographic Puzzle Hiding Scheme (CPHS) is used for submitting the session receipts to trusted node. The effectiveness of the proposed method has been proved from the simulation results based on packet delivery ratio, packet drop, residual energy, and overhead.