01-09-2014, 02:31 PM
Secure Communications Over Wireless Broadcast Networks: Stability and Utility Maximization
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Abstract
A wireless broadcast network model with secrecy constraints is investigated, in which a source node broadcasts confidential message flows to user nodes, with each message intended to be decoded accurately by one user and to be kept secret from all other users (who are thus considered to be eavesdroppers with regard to all other messages but their own). The source maintains a queue for each message flow if it is not served immediately. The channel from the source to the users is modeled as a fading broadcast channel, and the channel state information is assumed to be known to the source and the corresponding receivers. Two eavesdropping models are considered. For a collaborative eavesdropping model, in which the eavesdroppers exchange their outputs, the secrecy capacity region is obtained, within which each rate vector is achieved by using a time-division scheme and a source power control policy over channel states. A throughput optimal queue-length-based rate scheduling algorithm is further derived that stabilizes all arrival rate vectors contained in the secrecy capacity region. Moreover, the network utility function is maximized via joint design of rate control, rate scheduling, power control, and secure coding. More precisely, a source controls the message arrival rate according to its message queue, the rate scheduling selects a transmission rate based the queue length vector, and the rate vector is achieved by power control and secure coding. These components work jointly to solve the network utility maximization problem. For a non-collaborative eavesdropping model, in which eavesdroppers do not exchange their outputs, an achievable secrecy rate region is derived based on a time-division scheme, and the queue-length-based rate scheduling algorithm and the corresponding power control policy are obtained that stabilize all arrival rate vectors in this region. The network utility maximizing rate control vector is also obtained.
EXISTING System
Although jointly considering secrecy, reliability, and stability for network utility maximization has the potential for significant impact in improving network performance and resource efficiency, this perspective has not been examined before.
One reason is because the physical layer approach to achieve security, which quantifies the measure of secrecy and greatly facilitates this joint design, has attracted considerable attention only recently.
However, broadcast communications make use of the open nature of the wireless medium, which presents a great challenge to achieve secure communication for individual users.
Proposed System
We have designed, developed, and implemented a compromised router detection protocol that dynamically infers, based on measured traffic rates and buffer sizes, the number of congestive packet losses that will occur.
Each and every packet is encrypted so that to prevent the data from eavesdropping. So the data is very secured.
Once the ambiguity from congestion is removed, subsequent packet losses can be attributed to malicious actions
Algorithm Description
RED monitors the average queue size, based on an exponential weighted moving average: where the actual queue size and weight for a low-pass filter. RED uses three more parameters in minimum threshold, Maximum, Maximum threshold. Using, RED dynamically computes a dropping probability in two steps for each packet it receives. First, it computes an interim probability, Further; the RED algorithm tracks the number of packets, since the last dropped packet. The final dropping probability, p, is specified to increase slowly as increases
Software Requirements
• Operating system : - Windows XP Professional.
• Coding Language : - Java.
• Tool Used : - Eclipse
Module Description
User Interface Design:-
Network Formation:-
Packet separation/Creation
Encrption