# Trustworthy Transaction Spreading Using Node Reliability Estimation in IoT Blockchain Networks
## 2 Previous Studies  
A decentralized network architecture was proposed for peer-to-peer IoT applications [3; 4; 5]. IoT applications apply blockchain technology to various fields [6] such as transportation [7], life services [8], data storage [9; 10], timestamp [11], monitoring [12; 13], and identity processing [14]. Blockchains are actively applied in supply chains [15], crowd detection [16], wearable nodes [17], security [18], and laws [19]. IoT agricultural application is one of the best fields for blockchain technology. [PERSON] [20] proposed an application for the censorship of agricultural supply. They used RFID and blockchain to ensure food quality and improve safety while reducing logistical losses. IoT node management is another application area of blockchain [21] for remote control of IoT nodes. Remote control between IoT nodes requires a secure transaction exchange. A public blockchain, such as Ethereum, ensures secure transactions by storing the public key for encryption in each IoT node. [PERSON] et al. [22] and [PERSON] et al. [23] presented security issues in the IoT environment. [PERSON] et al. [22] described the requirements and state-of-the-art solutions for IoT security. They discussed the applicability of blockchain as a key technology for solving IoT security challenges. [PERSON] et al. [23] classified data quality assurance methods in an IoT environment. A multilayered IoT blockchain architecture was proposed in [24]. The proposed architecture introduces a less complex blockchain software to configure practical IoT networks. The researchers measured the performance of the architecture using an Intel Edison board and IBM Bluemix-based IoT nodes. A similar architecture was proposed in [25]. They presented the use of edge and higher layered architectures to deploy blockchain software. [PERSON] [15] discussed a cloud-centered architecture that includes IoT nodes in a blockchain. Building an IoT blockchain network using cloud architecture is ineffective because the cloud itself can be a failure point. [PERSON] et al. [26] proposed software-defined networking (SDN) for deploying blockchain in IoT networks. They developed blockchain network functions for the IoT nodes. An efficient operation strategy for IoT blockchains is vital for practical applications. As it increases the transaction exchange within the IoT blockchain network, blockchain network nodes condense the transaction data. Compact blocks [27], graphene [28], and Xthin blocks [29] provide block compression methods for efficient block sharing. Relay functions such as Falcon [30] and Fibers [31] are dedicated to efficient transaction spreading within a network. IBM's ADEPT [32] model uses a distributed network structure in an IoT environment. However, because ADEPT predefines and limits the roles of network nodes, it is difficult to provide network operation flexibility in IoT networks where nodes are frequently relocated. Ardor [33] proposed regional transaction spreading to prevent performance degradation in networks while ensuring transaction integrity. However, the ardor does not provide sufficient cases of regional spread. Reliability measurements on blockchain networks are underway to prevent malicious node behavior. In the Internet of Service (IOS), the personal information of the block builder and the number of tokens held were presented as a reliability score [34]. [PERSON] et al. [35] used a reliability score to select the cluster heads of mobile ad hoc networks and spread reliable transactions. The cluster head measures the reliability of the cluster's internal nodes and delivers them to the other cluster heads. A private blockchain is a network of reliable nodes. Therefore, it uses a simplified consensus algorithm. Artificial intelligence delegated proof of stake (AIDPoS) is a consensus algorithm presented by [PERSON] [36]. The consensus algorithm traces the reliability of the node and grants block generation rights. The reliability is quantified using the number of tokens that have been staked.