Mecanismele de consens blockchain

In principle, any node within a blockchain network can propose adding new information to the blockchain. To validate that this addition of information (eg a transaction record) is legitimate, the nodes must reach some form of agreement. This is where a "consensus mechanism" comes into play. In short, a consensus mechanism is a predefined specific (cryptographic) validation method that ensures correct sequencing of transactions on the blockchain. In the case of cryptocurrencies, such sequencing is necessary to address the problem of "double spending" (ie the problem that the same payment instrument or asset can be transferred multiple times if the transfers are not centrally recorded and controlled.