What is blockchain?
Blockchain is a distributed database, consisting of consequently connected blocks. The main difference between blockchain and a regular database is decentralization, that is, the absence of a managing intermediary that can make changes. In a centralized network, the server performs its role, and other users have to trust it.
In blockchain, data is distributed among participants that can be located at any distance from each other. Each of them:
- Stores the copy of the same ledger.
- Has access to all data.
- Can add new information.
Adding new data to blockchain is possible only after its validation (authenticity verification) by other participants. The verification is not carried out manually but by solving a certain complex mathematical puzzle. It is being performed by the so-called miners. Once a transaction is verified, a miner adds the information about it to a new block, which he sends to the rest of the network participants.
After the authentication process, data is added to blockchain as a part of a new block. It is important to stress that it is always placed in the end of blockchain, each time new data forms a new link in the non-breaking chain. It is impossible to change already formed and previously added blocks.
Blockchain technology became known with the popularization of cryptocurrency and is being used in an increasing number of life spheres, including the public sector. However, the implementation of this technology is not always justified.
Blockchain is necessary if:
- There is a need to use a reliable immutable database.
- The information in the database should be accessible to many participants.
- Participants do not trust each other.
- There is no need in a third party that participants can/should trust.
In other cases, the usual centralized database will be quite enough.