Eitaro Kohno

Secure decentralized data transfer against node capture attacks for wireless sensor networks

In wireless sensor networks, sensor nodes have limited computational power and memory size. The data is vulnerable to attack due to the nature of the systems, so maintaining confidentiality is an important problem. Most security methods are based on common or public key cryptosystems. However, these methods have problems with encryption of data. When nodes try to encrypt data, they must preestablish keys. When nodes send data to the sink node, all of the exchanged information will concentrate in the sink node. This creates a single point of failure. In this paper, we propose a new distribution method resilient against node capture attacks using the Secret Sharing Scheme. In addition, we will confirm the ability of our method to improve resiliency against node capture attacks, comparing it with TinySec, which is the major security architecture of wireless sensor networks. Also, we compare the resiliency to existing pairwise key establishment methods.

Improvement of assurance including security for wireless sensor networks using dispersed data transmission

Assurance networks are one of the essential technologies of New-generation Networks. Assurance is defined as the capability of guaranteeing functional and non-functional system properties such as dependability, security, timeliness and adaptability to heterogeneous and changing requirements. Assurance is essential for sustainable networks and this research focused specifically on providing assurance for WSNs. Node capture attacks are one prospective kind of attack on WSNs. To reduce negative effect of node capture attacks, we have previously proposed secure decentralized data transfer. In this proposed method, it was assumed that multiple paths were in place. In this paper as well, we again propose using the multipath routing method. To make multiple paths fit our previously proposed method, we have modified ATR (Augmented Tree Based Routing). We have conducted simulation experiments using our proposed method in a network simulator. The results show that our previously proposed method is effective in both cases in which the network size is small or large. In addition, we conducted other simulation experiments to measure several aspects of the assurance of our method. We measured in terms of varying parameters such as node densities, distance between the source and the destination nodes, and so on. Additionally, our method is more assured than the single path-based method.

A Self-Configurable New Generation Children Tracking System Based on Mobile Ad Hoc Networks Consisting of Android Mobile Terminals

Hiroshima City Children Tracking System is a safety support system for children based on ad hoc network technologies. Field experiments have been conducted in cooperation with an elementary school in Hiroshima. In this paper, we propose a new generation children tracking system which is based on experiences and findings of the field experiments for Hiroshima City Children Tracking System. Our proposed system consists of Android terminals which has Wireless LAN device and Bluetooth device with the ad hoc communication function. Our system manages groups of Android terminals using Autonomous Clustering technique. In this paper, we show the system requirements for our children tracking system and describe the implementation features to satisfy the system requirements. Finally, we provide some preliminary implemented results for our proposed system.

A Multipath Routing Method with Dynamic ID for Reduction of Routing Load in Ad Hoc Networks

In recent years, ad hoc networks have attracted a great deal of attention. Ad hoc networks consist of nodes with wireless communication devices without any base stations or fixed infrastructures. Most routing protocols of ad hoc networks form a single-path. Single-path routing protocols need to repair routes each time the route has broken. This route repair generates a lot of control packets, and an increase in end-to-end packet delay. In order to compensate for these drawbacks of the single path routing, multipath routing schemes have been proposed. AOMDV (Ad hoc On-demand Multipath Distance Vector routing) is one multipath routing scheme. AOMDV constructs routes by flooding Route Request (RREQ) messages. When the number of nodes increases in the network, the routing load of AOMDV, which is defined as the ratio of the number of control packets to the number of delivered packets, may increase immensely. On the other hand, DART (Dynamic Address RouTing) has been proposed for a large scale network. In DART, the dynamic routing address has a tree-based logical structure related to connectivity between adjacent nodes. In this paper, we propose a multipath routing scheme to solve the above problems of AOMDV. The proposed scheme is an extension of DART for dealing with multiple paths. The proposed scheme aims to reduce the routing load and adapt to large ad hoc networks. We evaluated its performance by comparing it with AODV and AOMDV through simulation experiments. Performance metrics are the number of control packets and the routing load. Simulation results indicate the proposed scheme can reduce the number of control packets and the routing load.

A Data Transfer Scheme Using Autonomous Clustering in VANETs Environment

An ad hoc network is a decentralized network that consists of mobile nodes with wireless communication devices without the aid of access points. A Vehicular Ad-hoc Networks (VANETs) is one of the representative application of ad hoc networks. Epidemic Routing has been proposed as a routing protocol based on Store-Carry-Forward mechanism for VANETs environment. However, in Epidemic Routing, network resources such as packet buffer of a node are significantly consumed because data packets are spread across the network. Therefore, this paper proposes a new data forwarding scheme that combines Epidemic Routing and autonomous clustering for VANETs environment. The proposed scheme configures multiple clusters in the network and then only the cluster head that manages the cluster stores and forwards data packet to mitigate the consumption of network resources. Finally, this paper presents the simulation results to show the effectiveness of the proposed scheme.

Improvement of Assurance for Wireless Sensor Networks Using Packet Detouring and Dispersed Data Transmission

Wireless sensor networks (WSNs) are an important direction for the Internet of Things. Node capture attacks are one prospective kind of attack on WSNs. To counter this attack, we have previously proposed secure decentralized data transfer. In this proposed method, it was assumed that multiple paths were in place. We also have to consider node failures when we design the data transfer method on WSNs. The data transfer methods have to deal with node failures and have to be dependable. In this paper, we propose a data dispersal method which aims to improve security and dependability features. To improve the dependability of our previously proposed method, we modified our routing method to be able to detour data packets en route when node failure occurs. We conducted simulation experiments using our proposed method in a network simulator. We measured in terms of varying parameters such as the number of shares, the threshold for the secret sharing scheme, the distance between the source and the destination nodes and so on. Additionally, we conducted simulations assuming node failures would occur in the environment. The results show that our method assured security and dependability features better than the single-path based method.

A New Generation Children Tracking System Using Bluetooth MANET Composed of Android Mobile Terminals

We have been developing a New Generation Children Tracking System using Android terminals which is based on experiences and findings of the field experiments for the Hiroshima City Tracking System executed in 2007. In the developing System, Android terminals communicate with each other with Bluetooth and configure a Bluetooth MANET. Also, they configure clusters autonomously by exchanged information. Tags in the Mesh Network use Wireless LAN to communicate with neighbor tags. They communicate with each other using the ad hoc routing protocols. We implement Secret Sharing Scheme for secure their end-to-end communication. In ATC2012, we plan to show the demonstration that Android terminals configure clusters autonomously and tags in the Mesh Network deliver cluster information to the server.

A Store-Carry-Forward-Based Data Transfer Scheme Using Positions and Moving Direction of Vehicles for VANETs

VANET (Vehicular Ad-hoc Network) that is used for vehicular-to-vehicular and vehicular-to-roadside communication is well known as one of the representative application of ad hoc networks. One of the representative mechanisms is Epidemic Routing that adopts the concept of Store-Carry-Forward. However, in Store-Carry-Forward mechanism, each node stores data packets in the buffer, and whenever the node meets at another node, it forwards the duplicated data packets. Therefore, this paper proposes a new reliable data forwarding mechanism that combines Epidemic routing, and the positioning information and moving direction of a node obtained from Global Positioning System (GPS) to reduce widespread forwarded data packets. The proposed scheme forwards data packets using the Store-Carry-Forward mechanism to the neighboring nodes that are determined by the positioning information and moving direction of a node. As a result, we confirmed that the proposed scheme has better performance than Epidemic routing with respect to the total volume of forwarded packets and consumed packet buffer through simulation experiments.

Performance improvement of Hiroshima City Children Tracking System by correction of wrong registrations on school routes

Recently, in Japan, crimes against children become atrocious and brutal. In some cases, children are attacked on the way to and back from school. Many technologies using ubiquitous networks have been developed to prevent crimes against children on their way to and back from school. Existing technologies, however, are not powerful to prevent crimes against children and helpful for parents since it is difficult to take information of children as a group. If the system can provide group information of children on the way to and back from school, it is easy for parents to know their safety level. This paper proposes a new technology for Children Tracking System based on mobile ad hoc networks and describes outline of Children Tracking System in Hiroshima City. The field experiments using the Children Tracking System have been performed and the effectiveness of the system is shown by data analysis for the experimental results.

The Assessment Information Acquisition and Dissemination System Based on Delay and Disruption Tolerant MANETs for the Hiroshima National Confectionery Exposition

In the Hiroshima National Confectionery Exposition which was held from April 19 to May 12, 2013 in Hiroshima, people who participated in the Expo sampled a wide variety of confectioneries and assessed variously, for example, they are sweet and beautiful. The assessment information acquisition and dissemination system proposed by us disseminates the information using store-and-forward data transmission based on delay and disruption tolerant mobile ad hoc networks. The system can adapt to sparse and dense network environments. If a node cannot forward information to any nodes immediately, the node saves it, moves toward them, and forwards it to them. People enjoyed the Expo like a game by exchanging the information in real-time or store-and-forward. In this paper, we show the characteristics of the system, the system overview including both the software for dissemination of the assessment information using Android smartphones and the user interface (UI) of the application on the screen of Android smartphones, and finally field experimental results.