• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.2
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• pp.53-64
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• 2005

Previous secure routing protocols for wireless sensor networks assume that a sink is static. In many cases, however, a sink operated by man or vehicle is moving. A mobile sink creates a lot of technical problems such as reconfiguration of routing path exposure of sink location. and selection of secure access point node, which are not considered by many previous researches. In this paper, we propose a new secure routing scheme for solving such problems using hi-directional hash chain and delegation nodes of grid structure. This scheme provides a secure routing path and prevents attacker from recognizing the location of a mobile sink in sensor networks. This new method reduces the resource requirements compared to the cashed routing schemes. Simulation results also show that the system is secure and efficient enough.

• Smart Media Journal
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• v.9 no.4
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• pp.91-96
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• 2020

A blockchain is a technology in which all nodes participating in a distributed network manage each transaction's contents without a central server managing the transaction, which is a record of the transaction. The block containing the transaction record of a specific period is connected to the blockchain by referring to the hash value for the previous block, and the chain with the new block added is shared with all nodes again. Transactions using existing certificates will pass through FinTech, and in the near future, applications using blockchains are expected to emerge. In this study, we analyze the problems of the existing model, and propose a transaction model that applies the blockchain to come. Among various applications, this study develops a trading model targeting the energy sales market among the topics that will lead the fourth industrial revolution. As a result of analyzing the proposed model, it was possible to be sure of the possibility of a safer energy sales transaction than the existing method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.2
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• pp.377-391
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• 2019

Recently, system studies using tokens and block chains for authentication, access control, etc in IoT environment have been going on at home and abroad. However, existing token-based systems are not suitable for IoT environments in terms of security, reliability, and scalability because they have centralized characteristics. In addition, the system using the block chain has to overload the IoT device because it has to repeatedly perform the calculation of the hash et to hold the block chain and store all the blocks. In this paper, we intend to manage the access rights through tokens for proper access control in the IoT. In addition, we apply the Tangle to configure the P2P distributed ledger network environment to solve the problem of the centralized structure and to manage the token. The authentication process and the access right grant process are performed to issue a token and share a transaction for issuing the token so that all the nodes can verify the validity of the token. And we intent to reduce the access control process by reducing the repeated authentication process and the access authorization process by reusing the already issued token.