# Mining

The process on which PoW consensus is based upon. Miners use computational power through cryptographic hash functions to secure the network.

## How hash functions work

Mining is based on cryptographic **hash functions**. A hash function is a special kind of cryptographic process that generates a fixed amount of bits given an arbitrary input. An example of an hash function is SHA-256 (which is used to secure the Bitcoin blockchain or Keccak-256 (used in Ethereum).

Hash function are one-way functions, this means that it is easy to derive the output given the input, but it is *computationally infeasible* to do the opposite; this means that one cannot retrieve the original input given the output of the hash function. Also, for any given input there is a unique output such that, even if only 1 bit of the input is altered, the output changes completely and is completely unrelated from the previous one.