Haruko Kawahigashi

Security Aspects of the Linear Network Coding

We study security aspects of linear network coding. We propose a quantity to measure how difficult for an attacker to obtain confidential information on the encoding scheme through wire-tapping, the wire-tap robustness (WTR). We expect that this measure will give a useful criterion for such robustness when one designs a network. We also propose an extra method to increase security against such wire-tapping.

A Proposal for a New Measure Analogous to Entropy for Bandwidth Constrained, Control-Based Ad-Hoc Network Design

In an ad-hoc network where available bandwidth is limited, the amount of transmitted data needs to be reduced. Especially in mission-critical ad-hoc networks such as tactical or disaster rescue networks, the bandwidth constraints are much more severe than in commercial or general public networks. In order to decrease the data amount, flexibility of the transmitted information should be limited. In traditional information theory, the basic criterion for effectiveness of coding is entropy based on probability. In this paper, we propose a new measure, urgency index and urgency entropy, to evaluate the effectiveness of coding in urgent communication and discuss its usefulness for designs of bandwidth constrained, control-based ad-hoc networks from a viewpoint of utility functions and elasticity

Least-hop path planning using neural networks

Recently, application of neural networks using their parallel processing feature has progressed. This paper proposes a routing method using a neural network and based on dynamic programming. The proposed method finds the least-hop path between two points in a communication network. The method consists of the application of disturbance to the destination, propagation of the disturbance to the source, and search for the shortest path from the source to the destination, using the distribution of the influences of the disturbance at each node.