Blockchain, Consensus algorithm

The Block chain or block chain can be defined as a public ledger in which all transactions are stored in the form of blocks, it is a chain in continuous growth in which new blocks are automatically added according to the number of transactions. In the block chain we will use cryptographic techniques such as digital signatures and different consent algorithms for user security and the consistency of the stored data. Consider any block chain that follows the following characteristics. They are transparency, invisibility, continuity and decentralization with these characteristics that a block chain can work efficiently and save costs. Because a Block chain is a growing list of public access records, each user has a public and private key to view and sign transactions without any intermediary and can also be used and applied in other fields such as smart contracts, Iot, organizations financial. Because a transaction cannot be manipulated once placed in the blockchain, organizations must be honest when creating and signing transactions. Althoughit has great potential for building a system of future transactions, it faces some difficulties. The main concern is archiving because the size of the block chain increases as the number of transactions increases. In second place comes the loss of privacy in which the data are subject to losses and third comes the part of the algorithm. Here we cannot say which of all the algorithms, for example, pow, which is a test of labor wasting electricity and the POS test of participation, which makes the rich richer in the phenomenon. Therefore, depending on the application, it is necessary to use and implement our block chain accordingly.