Figure 2: Input data = hash function = hash value The technical design of the blockchain has evolved through a number of iterations by using hash-functions and a
mathematical operation which creates a trace or digest of the transaction. Like human fingerprints, hash-functions are one way to verify that the fingerprint matches a specific person, but without the ability to create the person from the fingerprint. Equivalently, a hash value (the result of applying a hash-function) uniquely identifies data and has the ability to recreate it. In figure 2, the industry standard SHA-256 hash function is used. This produces a fixed size 256 bit hash value no matter what the size of the original data.