Hash Function

Hash function or hashing is a way of generating a value or values from a text string, with the aid of a mathematical function. It is one of the most favored ways to enable security during the transmitting of a message for a specific individual only. A formula does the hash generation. That helps to protect the message against tampering.

In the blockchain, hashing works the same way by taking an input of a string of text that can be any length and then outputting a fixed length. The transactions are then input and run through the hashing math function (algorithm) which will produce an output with a fixed length.

The thing that makes this work is that the hash function is deterministic (no matter how many times you parse through the input, the result stays the same), quickly computed and it is infeasible for someone to get the pre-image that produced the output hash.