# Blockchain Integration in the Era of Industrial Metaverse
## 3 Beyond the Current Implementations--Blockchain 5.0
### Blockchain and Digital Twin  
Under the light of Industry 4.0, nine pillar technologies have been developed and researched. Among them, simulation as a whole and advanced simulation technologies and techniques, such as digital twins, have been at the center of attention [46]. Based on the illustration of the keyword network presented in Figure 10, it can be realized that blockchain technology is highly intertwined with the pillar technologies of Industry 4.0, including the digital twin, the Internet of Things (IoT), and Big Data analytics. Alternatively, the \"digital twin,\" as an umbrella term for advanced simulation technologies and techniques, is highly dependent on Big Data analytics and the direct connection of the physical system with its digital twin. Therefore, new challenges arise regarding the network architecture design to be adopted for information technology, data inference, privacy, and security, as well as trust beyond the physical boundaries of the company. As a result, blockchain technology can be efficiently implemented along with digital twins to achieve a greater degree of data security and privacy. Furthermore, due to the decentralized features of the distributed ledger, stronger bonds (i.e., trust) with the stakeholders of the supply chain network can be established [47]. In addition, emerging technologies such as blockchain and digital twins are crucial to the industry 5.0 revolution's rapid growth and employment [48]. It is challenging to optimize the network and make the most of scarce resources to enable secure transmission given the rising number of industrial IoT nodes. A digital twin can be realized as a closed-loop control system between the physical object and its digital representation, which is entirely dependent on the constant bilateral data exchange enabled by the utilization of sensing systems. [PERSON] et al., in 2023 [47], combined a digital twin with a distributed network (employing blockchain functionalities) in an attempt to enhance Industrial Internet of Things (IIoT) applications. Among the key contributions of this research work is the presentation of a Proof of Authority (PoA) trust mechanism for the Internet of Things (IIoT).  
Inarguably, the global pandemic caused by COVID-19 has stressed not only manufacturing systems but also severely affected supply chains. More specifically, through the last two years, it became more than evident that existing infrastructure and techniques used for the operation and management of supply chains are fragile, have a low level of flexibility, and are very susceptible to failure due to external disturbances [49; 50]. However, global production networks as well as global supply networks could benefit from the integration of blockchain, improving their resilience as a result of increased data access accompanied by increased privacy and security [51]. Another aspect covered in the above-mentioned publications is the traceability of products and resources through the information shared by the distributed ledger [52].  
An alternative approach to the integration of blockchain technology in digital twins has been proposed by [PERSON] et al., in 2020 [53]. Besides the operational strategy of the company,  
Figure 10: Keyword network for “blockchain,” “digital,” and “twin.”  
it is of equal importance for companies to have better insights throughout the entire lifecycle of their products. Therefore, with the utilization of blockchain, it becomes evident that issues regarding data management and storage, access, and sharing can be tackled with the implementation of a distributed network, the operation of a distributed ledger, and the application of a consensus mechanism between the different parties involved.