What is the general description of the secure hash function?

Secure hash function is a uniquely computed string of code of 256 bits which acts as a digital signature (fingerprint) in contrast with the public-key cryptography.

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To learn more about secure hashing view the answer to the question "What is the distinction between a key's fingerprint (digital signature) and the key itself?".

To calculate secure hashing in theory:

• Calculate a sample that is smaller than the original but is absolutely true in value.
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  At this point, it is enough for you to figure out that the fingerprint is accessible so you do not have to calculate the whole document. It is highly unlikely to find two documents with the same fingerprint.

• Confirm you have the same key because you have the same fingerprint.
  • Your fingerprint combination is 2 to the power 256 (the total known number of particles in the universe is 2 to the power 100).
  • A small difference in input triggers a huge difference in output.

To sum up, we do not have to steal your key if we make the system believe that our key is the right key. However, to achieve that, we must spend a very, very long time calculating all your fingerprint combinations.

Did you know?

The most advanced world quantum computer can calculate up to 2 to the power of 25 combinations.