## 1 Introduction  
Distributed ledger technologies (DLT) enable the functioning of distributed ledgers, i.e., ledgers that are shared among multiple participants that form a network and synchronize with each other using consensus protocols. When developing distributed ledgers, they are tamper-proof, append-only, and immutable. The ledgers should only contain confirmed and verified transactions. In other words, distributed ledger technologies can provide a high level of security, transparency, and immutability, making them well-suited for use cases involving the transfer of digital assets or the recording of digital transactions. The most well-known and widely used example of distributed ledger technology is the blockchain. Distributed ledger technologies can be used in a wide variety of industries and applications, such as financial services, supply chain management, digital identity, games, and more. Distributed ledger technologies can offer many potential benefits, especially in terms of security, transparency, and decentralization. At the same time, they also have limitations such as scalability and cost. These technologies are still in the process of active development and improvement. One of the important areas of application for blockchain technology is the Internet of Things (IoT). The Internet of Things refers to a network of physical devices, vehicles, home appliances, and other items that are embedded with electronics, software, sensors, and network connectivity which enables these objects to collect and exchange data. The Internet of Things allows these objects to be sensed or controlled remotely across existing network infrastructure, creating opportunities for more direct integration of the physical world into computer-based systems, resulting in improved efficiency, accuracy, and economic benefit. The Internet of Things is expanding at a rapid pace; for example, from an analytical report [1], it suggested that the number of IoT devices connected to cellular networks will grow to 4.3 billion by 2026. For comparison, according to results from 2023, this indicator was estimated at 3.3 billion. Currently, most IoT solutions rely on a centralized server-client paradigm, connecting to cloud servers over the Internet. While this solution may work as expected for the time being, the huge growth in connected devices is causing problems in many areas, including data integrity, security, and reliability. Distributed ledger technologies can help solve the problems of traditional IoT applications, including the following:  
* Ensuring the integrity of IoT data without the participation of a third party, while maintaining the bandwidth and computing power of IoT devices;
* Ensuring the confidentiality of information transmitted over networks without a centralized server;
* Providing identification and authentication functions while tracking sensor data measurement and transmitting data between IoT peers without a central server;
* Lowering IoT operating costs by allowing smart devices to make automatic micro-transactions. Currently, one can observe an increase in the number of applications combining blockchain technology and the Internet of Things [2; 3]. Several cases illustrate the combined use of blockchain technology and the Internet of Things in the logistics sector. In 2020, major logistics company SF Express began using a blockchain-based tracking system for key shipments. Well-known food manufacturer Nestle uses blockchain and the Internet of Things to ensure the real-time tracking of agricultural products. Logistics giant DHL uses blockchain and the Internet of Things to improve the transparency and efficiency of its supply chains. German company BayWa Global Produce, a wholesaler and retailer of agricultural and industrial goods, uses the SIGNiT blockchain solution to optimize the logistics of fresh produce in collaboration with Giesecke+Devrient (G+D).