Today, the Internet of Things (IoT) technology is applied everywhere, providing tremendous amounts of IoT service. The GS1, a non-profit international standards organization, has established standards for IoT technology. Especially, the GS1 standardized an Object Name Service (ONS) leveraging DNS's distributed and federated infrastructure, enables users to manage and discover IoT services such as the retail, food, healthcare, smart city, and so on. However, the ONS is vulnerable to the data tampering, privilege escalation, and service fault caused by DNS attacks including the man in the middle, cache poisoning, replay, hijacking, and denial of service attacks. Nowadays, IoT services are used in security-sensitive areas, such as finance and healthcare. Therefore, the security of ONS should be strengthened before causing severe problems such as data breach, economic loss, and social loss. In this paper, we propose a blockchain-based ONS with a tokenized authority called the BlockONS. The BlockONS provides strength in the data tampering and privilege escalation allowing a fault tolerance. The BlockONS consists of a content off-chain scaling, a data tampering validation method, a fault-tolerance method, and a Blockchain Token-Based Access Control (BTBAC) method. We designed the BlockONS into two parts: A BlockONS Node part manages the validation method and BTBAC model. A BlockONS Agent part manages the off-chain scaling and fault tolerance. Finally, we implemented the BlockONS leveraging a Hyperledger Sawtooth blockchain. We proved the proposed validation method, fault tolerance method, and BTBAC method through use cases and security analyses on attack situations. We deployed the BlockONS in the Daejeon city and evaluated the performance to show the feasibility of the BlockONS.

In food service, the transparency and reliability of product data are especially important requirements. But most of distributed information is non-trusted data without accurate source. To provide reliable data of food products, we propose the metadata service architecture for food service, applying GS1 Source defined by GS1 (Global Standard 1). GS1 Source is a standard for providing a communication of authentic and accurate product data between brand owners and consumers. We implemented the metadata service architecture as a java web service. The implemented architecture was applied in real food service and verified feasibility. We tested the performance of the web service by estimating request time, error rate, and response time, and conformed sufficient performance of the service. By applying GS1 Source to the food system, we can contribute to food service ecosystem with trusted data.

To ensure global interoperability in today's fast-moving trading networks, EPC global Network (EPC Network) architecture has been at the core of Electronic Product Code (EPC) as a universal identifier for objects' virtual representations. While Cloud technology has largely been used for EPC Network's real world deployment for thousands of vendors, an optimized Cloud solution has yet to be provided. Therefore, in this paper, we explore the challenges of EPC Network deployment, and propose our own Cloud solution with optimizations in load prediction and migration management. As proof of concept, we have conducted experiments with regard to prediction accuracy and migration performance.

Service-oriented computing which provides flexible composition of various applications using multiple reusable services has getting more attractive. We propose a service oriented wireless sensor networks toolbox, which encapsulates complexities of sensor networks and enables simple service compositions using an intuitive GUI. We utilize sensor networks as a collection of services that are discovered and coordinated by users. Service metadata which are self-describing service capabilities and interfaces are defined and exposed via our service metadata repositories. A service oriented sensor network toolbox consisting of sensor networks, an intuitive GUI application that retrieves metadata for discovered services and helps users to composite various roles are presented.