Blockchain

The blockchain is a method of registration that stores information and its changes on all machines connected to the system. The great advantage of this decentralized operation is that no one can arbitrarily rewrite the past, but all users can make changes compared to the last state.

Blockchain covers a technology in which new information contained in blocks (such as a transaction) can and must always be appended to the end of the blockchain. Thus, it is actually a database that contains all transactions from the beginning. 

Each block has its own unique “hash”, that is, its encrypted identifier, which is created from the data of the block with the help of mathematical operations. This "hash" also contains the identifier of the block preceding it. And the "hash" before it is the one before it, and so on until the first one. 

As soon as we want to modify even one character in the block, the "hash" changes, so the chain is broken and becomes invalid. For this reason, the blockchain, i.e. the data, is practically unbreakable and unforgeable. In essence, the blockchain is therefore a record system that cannot be copied afterwards. 

Not only the way the database is built, but also chaining into blocks guarantees security. Since with the performance of today's computers, it is possible to recalculate many, many "hash" in minutes, so an "authentication work" is built in, which precedes the creation of a new block. 

The third element of the protection system is decentralization, meaning that the entire database, the "ledger", is accessible to all participants. The ledger is therefore not stored in a single, central location, so it is not possible to falsify the data in a single location. 

The blockchain was created by cryptocurrencies (for example the Bitcoin) made known, but the use of the technology is now much wider than the universe of cryptocurrencies. Many see great potential in it because there is no need for intervening institutions (banks, lawyers, notaries) to ensure that the stored and sent information and transactions are authentic. Certain processes can be made much cheaper, much faster and safer thanks to this. Blockchain can be an important technology fintech in developments, in the management of self-driving cars, in the creation of smart contracts, and in proving the origin of manufactured products.

In addition to all this, due to the role of its authentic record, blockchain can expect even more general spread. A good example of this is related to the acquisition of qualifications and educational institutions. Distributed ledger technology is expected to renew the authentication of personal documents, which can significantly simplify the management of administrative matters.