Enhanced CCTV Enclosure Record Management Model through DAG Blockchain

Managing enclosures is necessary in order to safely transfer video stream of public CCTV. Smart enclosure monitoring system provides efficient management by providing operating status and environment of enclosures and blockchain based enclosure record management system provides data integrity to this end. However, the blockchain with linear structure has a limit on data rate for storing depending on the block generation cycle and size. If the amount of data over this limit, a bottleneck occurs. The bottleneck reduces availability of the system. Therefore, this paper proposes a directed acyclic graph blockchain based CCTV enclosure record management model to reduce the bottleneck. This model stores the record in blockchain of DAG structure and maintains its integrity. The blockchain increases throughput and reduces the bottleneck of the linear blockchain by storing multiple blocks at the same time. To evaluate the performance of this model, an experiment simulating the confirmation time of linear and DAG blockchain was conducted. As a result the linear blockchain showed a maximum time of 859 seconds and the DAG blockchain showed a maximum time of 12.9 seconds in an environment composed of 1500 nodes, confirming that the bottleneck was reduced.