Bitcoin uses the SHA-256 algorithm for hashing. This hash function has some interesting properties as follows: Deterministic: This means it will always yield the same output for exactly the same input. No matter what.   Avalanche Effect: The output changes drastically for the slightest change in the input. This means the output will change completely even if you have added a comma in the document.    One-Sided: The output can never be traced back to its input.