# Leveraging the Internet of Things and Blockchain Technology in Supply Chain Management
## 5 Combining IoT with Blockchain Technology: Emerging Research Areas
### Scalability
Moreover, the design of IoT-specific consensus protocols would benefit the integration of a Blockchain in an IoT-based supply chain and create opportunities for developing content-oriented consensus protocols. Collectively, these advancements will enhance the integrity of sensory data through the cross-validation with the sensory data from other IoT nodes and historical data [92]. Sharding is a novel mechanism to alleviate scalability by distributing contents of a database across nodes in a network [93]. Partitioning a Blockchain might be especially suitable for IoT-enabled supply chains where the main chain handles less frequent global events (e.g., global transshipments, containers operations, disaster monitoring, and emergency plans) while secondary chains are established for recording frequent local transactions and logistical events of interest only to regional networks (e.g., inbound logistics, production monitoring, inventory control) [73]. However, the consistency and efficiency of inter-communication among Blockchain shards remain a challenging task to maintain. For example, the need for a scalable distributed ledger for IoT devices has resulted in the emergence of alternative data structures such as IOTA. Unlike traditional Blockchains, IOTA is a distributed architecture build upon a DAG called Tangle [90]. The tangle serves as a data structure that offers a set of significant advantages, including scalability, efficiency, fee-less, and real-time transactions [94]. Every node that registers a transaction has to verify two other transactions before its transaction is verified, which significantly speeds up the validation process. The Tangle meets the requirements of storing massive amounts of data and high-speed access to them. Moreover, its design introduces a new approach for reaching consensus and resolves the (often prohibitive) fees for microscale transactions required by IoT sensing and actuating use cases [95]. This implies that the applications of IoT in the supply chain will be enabled by a supporting platform that moves toward a more efficient and economic machine-to-machine interaction. In the case of multi-directional and tightly integrated supply chains, this might further lead to potential cost-savings and opportunities to generate new revenue streams. For instance, IOTA offers an IoT marketplace wherein sensor data can be bought and sold using Blockchain technology [96]. Various use cases illustrate the ability to transfer sensor data from the physical layer to the service layer more rapidly and securely, leading to real-time streamlining of transactions and better evaluations of different scenarios and tradeoffs (e.g., the choice of suitable protocols), and more increased micro-level IoT integration [97]. Even though existing proposals for enhancing scalability are confronted by the difficulty to combine decentralization, scalability, and security, the scalability of Blockchain technology is not necessarily an inherent problem for its integration with IoT-based supply chains. Likewise, many innovative and more scalable solutions are still under development to make Blockchain technology a key catalyst for transferring value and efficiently allocating resources among IoT networks in the foreseeable future. Parallel to this approach, Blockchain technology is reinventing cloud computing technology in that it facilitates greater levels of IoT scalability and mobility [98]. A practical use case that has emerged from coupling Blockchain with cloud storage is the IBM Watson IoT Blockchain which operates in a cloud environment and helps to process massive amounts of data among heterogeneous devices [31]. To empower IoT devices and sustain their operations in a completely trustless ecosystem, [PERSON] et al. [99] propose the combination of service-centric networking (SCN) and Blockchain technology, in which the Blockchain is backed up by the ubiquitous IoT devices mobility and the global scalability offered by SCN.