Thanks to asymmetric cryptography and hash functions (a mathematical algorithm that transforms any arbitrary block of data into a new series of characters with a fixed length), it becomes a unique cryptographic model. This feature allows you to create a consensus on the completeness of the data by all network participants without the need to resort to a central trusted entity that stores the information, for this reason the system is reliable and the information is built, strengthened and consulted securely by the members of the network.
In case of an attack or spoofing the nodes (sybil nodes) the attacker would require a greater presence and computing power than the sum of all the remaining nodes in the network making this process almost impossible.
In summary: Blockchain is a technology designed for digital ecosystems in which it is necessary to store data in a growing way ordered over time. Data without the possibility of modification or revision and whose trust must be distributed instead of residing in a certifying entity.
All this under the following guidelines:
1. Data storage model: Consists of the way in which the information is replicated in the blockchain.
2. Data transmission: This is achieved through peer-to-peer networks that receive and transmit the information.
3. Data confirmation: This is the process of consensus among the participating nodes. It consists of the consensus algorithm, the most widely used is the proof of work. This is an open competitive and transparent process of validation of new entries called mining.
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Rafael Rojas Moncada