# Leveraging the Internet of Things and Blockchain Technology in Supply Chain Management
## 5 Combining IoT with Blockchain Technology: Emerging Research Areas
### Immutability and Auditing  
The integration of Blockchain technology with IoT devices advances supply chain automation and creates an ecosystem consisting of immutable transactions that allow for improved audit. Supply chains exchange partners gain from the combined application of Blockchain and IoT through safe and auditable transactional data exchange within a massively heterogeneous and context-aware setting [108]. When connected on a network, smart IoT devices can consistently and autonomously push data into the Blockchain platform, creating an immutable and auditable transactional history which is useful for product traceability, recall, product provenance, and authentication purposes. Blockchain technology, thus, enables a fine-grained audit capability [109] where sensor values can add additional trust incorporating real-time and immutable data [110]. These characteristics sparked the attention of IoT technology providers who are adapting their IoT network-based solutions to Blockchain-based technology [111].  
In automating several supply chain activities, Blockchains can include and leverage smart contracts, a term first coined by [PERSON] in 1994 and predating Bitcoin's usage of Blockchain by more than a decade. A smart contract, such as an automated payment through a financial institution, is defined as a computerized protocol that executes the terms of a contract [112]. Intelligent contracts streamline processes, ensure privacy and enable supply chain exchange partners to take full advantage of automation efficiencies. This benefit is evident in the ability to process information streamed from IoT devices and networks without any downtime or human intervention and to support transactions between devices [100] safely. Smart contracts can be run and stored in the Blockchain system, and they guarantee the execution of rules in a pre-defined way. In doing so, they support auditing processes, and we postulate:  
RP3-1: The immutability of Blockchain technology positively impacts the auditing of IoT solutions.  
The idea of a'mutable' (editable, redactable) Blockchain comes as a response to the ever-increasing complexity of the ledger, evolving business environments and the incremental accumulation of blocks. Moreover, it may be directly related to the overall poor quality of product data across supply networks [113]. Thus, the mutable Blockchain has been proposed to reverse, delete, and add new blocks in the Blockchain [88]. Since supply chains are experiencing the proliferation of IoT device usage, the use of editable Blockchains could address data errors caused during this nascent stage of IoT's evolution. As such, transactions generated from IoT sources and replicated across the Blockchain network could be edited or removed while still maintaining an immutable audit trail. Examples include IoT data for products already consumed, deactivated tags or sensors, reusable tags or sensors, damaged or faulty tags or sensors, and outdated or retired/unusable technologies. Currently, firms are exploring the possibility of mutable Blockchains, changing the way hash pointers link blocks so that only authorized parties can modify past blocks [114]. Despite being intuitively contradictory to immutability as a key attribute of Blockchain technology, these mutable Blockchains create new opportunities but also raise new questions related to the rules and governance for performing edits and corrective actions. Thus, we postulate:  
RP3-2: Mutable Blockchain technology creates new application scenarios for IoT usage and management.