# Resource Management and Secure Data Exchange for Mobile Sensors Using Ethereum Blockchain
## 2 Related Work  
[PERSON] et al. [14] presented an elaborate discussion of blockchain applications in IoT, highlighting the essential operations. This study discussed the five-layer architecture of blockchain, emphasizing the fundamental interaction between the blockchain framework and IoT nodes to support numerous blockchain applications. Other studies have reported blockchain applications for supply chain management [15], energy trading [16], water management [17], waste management [18], forestry and agriculture [19], mineral traceability [20], and fishery management [21]. Based on these studies, almost every work revolves around applications that are more inclined towards its usage with the Ethereum blockchain. In addition, various studies have adopted the Ethereum blockchain application in smart cities, secure sensor communication, and resource management. Existing studies in this direction have been carried out to develop smart contracts for governance and transactions [22], where such contracts can automate various governance processes, such as permits, licenses, and property transactions, thereby reducing bureaucracy and increasing transparency. Ethereum-based decentralized identity solutions can enhance security and privacy in smart cities by providing secure and verifiable digital identities for residents,workers, and devices. These identities can be used for access control in sensitive areas, services, and data [23]. Furthermore, Ethereum's blockchain provides a tamper-resistant and immutable ledger for recording sensor data in smart cities to prevent unauthorized tampering or manipulation [24]. Subsequently, smart contracts can automate data validation, aggregation, and analysis, enabling real-time decision-making and optimization of city operations [25]. Ethereum's blockchain enables the tokenizing of physical and digital assets and services in smart cities to create new business models for sharing economy initiatives [26]. Ethereum-based decentralized data marketplaces can allow the exchange of valuable urban data among stakeholders, such as government agencies, businesses, researchers, and citizens [27]. Marketplaces can catalyze innovation in urban analytics, urban planning, and smart city development by incentivizing data sharing through token incentives and smart contracts. The usage of blockchain in IoT varies; however, it is more harnessed for accomplishing security objectives towards resisting various lethal threats. In this regard, trust management-based approaches have evolved more in IoT utilizing Ethereum. The work presented by [PERSON] et al. [28] has multiple trust management schemes for the service provider that contribute towards yielding a list of permissible and non-permissible operations by the nodes. The model can resist potential trust-based attacks. A trust-based approach using blockchain was also reported by [PERSON] et al. [29], which facilitates secure data transmission using asymmetric encryption keys in sensor networks. The attacker is identified using the delayed transmission, response time, and forwarding rate. Another unique trust assessment scheme was presented by [PERSON] et al. [30], where the framework for spectrum management using a blockchain was presented with a target to achieve higher privacy conservation. This study presents a trust-based evaluation in which the outcome resists the most trust-based attacks. [PERSON] et al. [31] presented a trust evaluation model using blockchain for smart marketplaces. The study outcome was observed to have a significantly reduced latency. Other reviewed studies on trust-based blockchain design have also been conducted by [PERSON] [32], [PERSON] et al. [33], [PERSON] et al. [34], [PERSON] et al. [35], and [PERSON] et al. [36]. [PERSON] et al. [37] presented an energy minimization approach for mobile edge computing in which blockchain was used to design a unique multiple access approach. This study addresses energy resource issues while securing applications for dynamic edge devices.