Anotace:
Smart IoT devices, such as lights, locks, washing machines, security cameras, etc., are becoming omnipresent in households and companies across all industries. However, most of these devices communicate over non-secure local protocols or via cloud services where security policies are not transparent. Vulnerabilities may lead to unauthorized access to such IoT devices. Blockchain is a technology that brings security by design and can be exploited also in the area of controlling access to IoT devices. The goal of the paper is to test the use of blockchain with IoT devices to increase the security of device usage while ensuring that the user experience remains efficient and user-friendly. Three approaches to use blockchain are proposed and tested: a) application without the blockchain using standard HTTPS protocol; b) an application using blockchain, where users sign the transactions themselves; c) an application using blockchain where the server signs the transactions. The paper successfully shows that blockchain can be used to enhance IoT device security, with an focus on user-friendliness testing to ensure the solutions are practical for everyday use.