Iwao Sasase

A Novel Blockchain-Based Product Ownership Management System (POMS) for Anti-Counterfeits in the Post Supply Chain

For more than a decade now, radio frequency identification (RFID) technology has been quite effective in providing anti-counterfeits measures in the supply chain. However, the genuineness of RFID tags cannot be guaranteed in the post supply chain, since these tags can be rather easily cloned in the public space. In this paper, we propose a novel product ownership management system (POMS) of RFID-attached products for anti-counterfeits that can be used in the post supply chain. For this purpose, we leverage the idea of Bitcoin’s blockchain that anyone can check the proof of possession of balance. With the proposed POMS, a customer can reject the purchase of counterfeits even with genuine RFID tag information, if the seller does not possess their ownership. We have implemented a proof-of-concept experimental system employing a blockchain-based decentralized application platform, Ethereum, and evaluated its cost performance. Results have shown that, typically, the cost of managing the ownership of a product with up to six transfers is less than U.S.

Unsupervised Clustering-based SPITters Detection Scheme

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Low false alarm rate RPL network monitoring system by considering timing inconstancy between the rank measurements

VoIP /SIP is taking place of conventional telephony because of very low call charge but it is also attractive for SPITters who advertise or spread phishing calls toward many callees. Although there exist many feature-based SPIT detection methods, none of them provides the flexibility against multiple features and thus complex threshold settings and training phases cannot be avoided. In this paper, we propose an unsupervised and threshold-free SPITters detection scheme based on a clustering algorithm. Our scheme does not use multiple features directly to trap SPITters but uses them to find the dissimilarity among each caller pair and tries to separate the callers into a SPITters cluster and a legitimate one based on the dissimilarity. By computer simulation, we show that the combination of Random Forests dissimilarity and PAM clustering brings the best classification accuracy and our scheme works well when the SPITters account for more than 20% of the entire caller.

Secret sharing based unidirectional key distribution with dummy tags in Gen2v2 RFID-enabled supply chains

The IPv6 Routing Protocol for Low-power and Lossy networks (RPL) is a standard routing protocol to realize the Internet of Things (IoT). In order to realize secure IoT network, the Destination-Oriented Directed Acyclic Graph (DODAG) root collects information such as neighbor and parent ranks in each node and then observes network consistency by comparing a rank that a node sends to DODAG root with the rank that the same node sends to its neighbor nodes. However, the scheme has a problem that false detection rate is high since the DODAG root might compare a certain nodes rank after update with its rank that its node sends to its neighbor nodes before update due to timing inconstancy between rank measurements. In this paper, we propose a low false alarm rate RPL network monitoring system by considering timing inconstancy between rank measurements. In the proposed scheme, each node sends ranks at the time when each node broadcasts the latest rank to the DODAG root so as to avoid inherent timing inconstancy, and each node attaches a timestamp at the time when each node sends and receives ranks and then sends the timestamp to the DODAG root in order to take timing inconstancy into consideration. We evaluate the false detection rates by computer simulation and we show that the proposed scheme reduces the false detection rate in comparison with the conventional scheme.

Secure parent node selection scheme in route construction to exclude attacking nodes from RPL network

Recently, a secret sharing scheme is found to be effective to solve the key distribution problem between parties in RFID-enabled supply chains. However, there is a problem that an attacker might recover the legitimate key by collecting sufficient secret shares when products are carried in the public transportation. In this paper, we propose an effective secret sharing scheme by introducing sufficient number of dummy tags which possess a bogus secret share when the tag-attached products are conveyed. Since an attacker cannot see the tags themselves from the outside of the carrying vehicle, he/she cannot distinguish between the legitimate tags and dummy tags and thus has to find out the correct key by iteratively trying each combination of secret shares. On the other hand, the party who receives products can distinguish dummy tags since they are not attached to any product. We also adopt a file privilege and untraceable option which are newly ratified by Gen2v2 (Gen2 version 2) to realize secure and practical RFID-enabled supply chains. We prove that our construction is secure in both the privacy and robustness aspect. We also confirm that our scheme is easily implemented with the off-the-shelf RFID reader and tags.

Reduced complexity on mobile sensor deployment and coverage hole healing by using adaptive threshold distance in hybrid Wireless Sensor Networks

The IPv6 Routing Protocol for Low-power and Lossy networks (RPL) is a standard routing protocol to realize the Internet of Things (IoT). Since RPL is a tree-based topology network, an attacking node may falsely claim its rank towards neighbor nodes in order to be chosen as a parent of them and to collect more packets to tamper. In this paper, we propose a secure parent selection scheme so that each child node can select a legitimate node as its parent. In the proposed scheme, each node chooses a parent after excluding the best candidate if multiple parent candidates exist. Our scheme utilizes the fact that an attacking node claims falsely a lower rank than that of a legitimate nodes. We show that attacking nodes have no merits to claim lower ranks than true ones in a secure parent node selection scheme. By the computer simulation, we show that the proposed scheme reduces the total number of child nodes attached to attacking nodes in comparison with the conventional RPL scheme.

Opportunistic routing protocol with grid-based relay slot selection in Energy Harvesting WSNs

The hybrid deployment of wireless sensors with static and mobile nodes in the monitoring area is an important issue to cover a maximum sensing area with a limited number of nodes. Furthermore, mobile sensor nodes can relocate themselves to improve coverage area in the network. In this paper, we propose a method that reduces the complexity on the relocation of initial deployment and coverage hole healing of mobile sensor nodes in the hybrid Wireless Sensor Networks (WSNs). Our method finds the best-ordered ways of mobile nodes movement to give the shortest distance movements for mobile nodes in WSN. Adaptive threshold distance is used to eliminate the consideration of some mobile nodes, which are already occupied or situated within the threshold distance from optimal new positions. The simulation results show that the proposed methods can give much smaller calculation time to find the shortest paths for the movements of mobile nodes in WSN.

Practical key distribution scheme with less dummy tags in RFID-enabled supply chains

Energy Harvesting (EH) technologies are getting attractive to realize the battery-less wireless sensing networks (WSNs). In EH-WSNs, opportunistic routing that the intermediate nodes relay packets is preferred due to the extremely constrained energy. However, in the conventional scheme, intermediate nodes rigidly determine its relaying slot by calculating distances between a source and a destination and this causes heavy computation for nodes. In this paper, we propose a lightweight grid-based relay slot selection scheme in EH-WSNs. In our scheme, we use square-shaped grid and divide the network virtually to give each node primitive coordination and each intermediate node decides its relaying slot by calculating the differential of grid-index between a sender and a receiver. Based on grid-based coordination, our scheme turns multiplications into lightweight subtractions and this reduces the computational complexity and required memory. In addition, we also propose a probabilistic relaying scheme to reduce collisions in each relaying slot. We evaluate the conventional and proposed schemes through the computer simulation and show that our scheme reduces the computational complexity and achieves comparable throughput to the conventional scheme.

Concurrent Moving-Based Connection Restoration Scheme between Actors to Ensure the Continuous Connectivity in WSANs

In RFID-enabled supply chains, in order to securely deliver products, a secret sharing scheme has been proposed. An encryption key of tags is split into shares and the key can be recovered with the sufficient number of correct shares. The conventional scheme introduces sufficient number of dummy tags with bogus shares and prevents an attacker who reads all tags during shipping from obtaining tag information. The number of required dummy tags is decided so that the success probability of the attack becomes lower than that in the brute force manner. When the number of shipping products is small, too many dummy tags are required to prevent the attacker from selecting correct shares with a small number of trial. In this paper, we propose a practical scheme which reduces the number of tags by using extra legitimate tags. An encryption key and its share for legitimate tags are assigned to not only the conventional legitimate tags but also extra legitimate tags, and thus, the number of legitimate tags is virtually increased. By doing this, the number of required dummy tags can be reduced. Extra legitimate tags are separately composed from conventional legitimate tags and dummy tags, then they can be distinguished easily. We show the effectiveness of our scheme by computer simulation.

High-Order Statistics for the Channel Capacity of EGC Receivers Over Generalized Fading Channels

In Wireless Sensor-Actor Networks (WSANs), sensors probe the surroundings and forward their data to actors. Actors collaboratively respond to achieve predefined application mission. However, since the environment where WSANs are used is usually complex and harsh, actors cannot communicate with its neighbor actors occasionally due to the failure of an actor. Although the recent work provides a connection restoration scheme between actors, disconnection intermittently occurs since each actor moves to new position one-by-one. In this paper, we propose a concurrent moving-based connection restoration scheme between actors to ensure the continuous connectivity. By sending a message to neighbor actor before moving, an actor can inform when it starts to move and where it moves to. Thus, neighbor actors which receive a message can calculate when it starts to move for concurrent move of actors. An actor starts to move when the communication with neighbor actors is unavailable due to neighbor actors move. Further, when the actor starts to move, it creates sub-paths to its moving neighbor actor for continuous connectivity. The network restoration time is shortened because of concurrently moving instead of moving one by one. We show that our scheme restores the network connectivity much robuster and faster than the conventional scheme by computer simulation.