A Novel Bi-Velocity Particle Swarm Optimization Scheme for Multicast Routing Problem

A nondeterministic polynomial (NP) with complete Multicast routing problem is defined using a bi-velocity particle swarm optimization (BVDPSO) is proposed in this paper. The shift of particle swarm optimization to the discrete or binary domain, stepping away from the continuous domain is the major impact of the work. Initially a bi-velocity strategy is built such that it characterizes each dimension in terms of 0 and 1. The basic function of this strategy is to describe the MRP’s binary characteristics such that 0 stands for the node not being selected while 1 stands for selection. Based on the location and velocity of the original PSO in the continuous domain, the BVDPSO is updated. This will preserve the global search ability and fast convergence speed of the original PSO. 58 instances of large, medium and small scales are used for experimentation in the OR-Library. Based on the results, it is identified that it is possible to get near-optimal or optimal solutions for BVDPSO as it requires generation of limited multicast trees. This approach is found to be optimal over its peers and outperforms recent heuristic algorithms and many advanced techniques used for the MRP problem. They also outperform several PSO, ant colony optimization and genetic algorithms.

Scalable and Anonymous Group Communication with MTor

This paper presents MTor, a low-latency anonymous group communication system. We construct MTor as an extension to Tor, allowing the construction of multi-source multicast trees on top of the existing Tor infrastructure. MTor does not depend on an external service to broker the group communication, and avoids central points of failure and trust. MTor’s substantial bandwidth savings and graceful scalability enable new classes of anonymous applications that are currently too bandwidth-intensive to be viable through traditional unicast Tor communication-e.g., group file transfer, collaborative editing, streaming video, and real-time audio conferencing.We detail the design of MTor and then analyze its performance and anonymity. By simulating MTor in Shadow and TorPS using realistic models of the live Tor network’s topology and recent consensus records from the live Tor network, we show that MTor achieves a 29% savings in network bandwidth and a 73% reduction in transmission time as compared to the baseline approach for anonymous group communication among 20 group members. We also demonstrate that MTor scales gracefully with the number of group participants, and allows dynamic group composition over time. Importantly, as more Tor users switch to group communication, we show that the overall performance and utilization for group communication improves. Finally, we discuss the anonymity implications of MTor and measure its resistance to traffic correlation.