Definicja hash function

An algorithm that you can apply to a message or text that guarantees the message's integrity.

The hash function generates a specific numerical value (hash value) from the original message or text. This number is substantially smaller than the original message and is generated in such a way that it is extremely unlikely that applying the hash function to a different message would produce the same hash value. In addition, the original file cannot be reconstructed on the basis of this value.