Blockchain is a record-keeping technology, essentially it is a distributed and decentralized public ledger. Often associated with cryptocurrencies, blockchain technology is widely used in traditional finance, e.g. by banks and insurance companies, as well as in many other areas, not related to finance. For example, blockchain technology may be used in smart contracts, supply chains, voting, cybersecurity. There are blockchain technology-based services, which allow to securely store personal data related to medical records, digital assets and property exchanges.