# Blockchain Integrated IoT for Food Supply Chain: A Grey Based Delphi-DEMATEL Approach
## 2 Literature Review
### Integration of IoT and Blockchain  
Several years ago blockchain was invented as a diffused records technology that enabled a series of time-stamped, immutable data records to be stored in a decentralized network, and it has been used in a diversity of applications, including finance [23], design [24], and agriculture [25]. It has been proven that blockchain's decentralised, verifiable, and immutable properties have facilitated its adoption as a tool for enhancing supply chain traceability and for ensuring product origin over the past few years [26; 27; 28]. Blockchain technology offers supply chain lucidity and ensures the consistency of all data recorded on a distributed record book. However, it is matter of the solicitude that blockchain does not possess the potential to verify the reliability of data exchanged by supply chain actors that is relevant to supply chain events in computer-to-human interactions, since it is incapable of verifying the integrity of data uploaded by supply chain actors [29]. For instance, [PERSON] et al. [30] proposed a blockchain-based healthcare information exchange platform for the storage and sharing of large amounts of healthcare data.  
It has been observed that the B-IoT could be an infusion to secure data sources as well as rectitude [31; 32; 33]. In order to collect and transfer data, it is not necessary to have on-the-scene or remote human interference, and that is made possible through the use of IoT devices [34]. By storing data on the blockchain system from IoT devices rather than human input, one can significantly reduce the probability of malicious data manipulation. The authenticity of the data will be enhanced, as well as the level of trust within the network. The integration of blockchain in IoT systems in order to ensure the safety and security of data [35; 36]. A number of studies have demonstrated the importance of blockchain technology and the Internet of Things in addressing the data-related issues of trust, security, privacy, and integrity [37; 38; 39]. In the digital world, the combination of blockchain and IoT would seem like an ideal match because they complement each other's limitations, but there are a number of challenges that must be overcome [40]. There are various challenges associated with blockchain implementation in IoT applications, including the need to deal with computation, storage, communication latency, and energy incompatibility, as previously reported [41; 42].  
Using blockchain as a transparent and transactional database, rapid and efficient generation and processing of information is possible. At the same time, IoT narrates the expansion of insert devices that can transmit data by way of a communication convention in order to provide data connectivity. There are many advantages that can be gained by integrating these two technologies [43]. It is difficult to integrate blockchain technology into IoT due to the constraints of limitations such as scalability, bandwidth, storage capacity, privacy, and legal permissions [44]. [PERSON] et al. [45] suggested that the FSC players should be able to obtain reliable and efficient tracing facts, goods and benchmarking data using B-IoT. Through B-IoT, privacy, security, data access control, and reporting issues can be identified [46; 47]. In addition to increasing scalability, the integration of B-IoT will reduce third parties' participation in the business operation [48; 49]. Practitioners should develop plans for validating IoT data before processing it into the blockchain, because imprecise or invalid information can damage trust [46].