Internet of Things for Architects

Cryptographic hash (authentication and signing)

Hashing functions represent the third type of cipher technology to consider. These are typically used to generate a digital signature. They are also considered "one-way" or impossible to invert. To recreate the original data after passing through a hash function would be a brute-force attack of every possible combination of inputs. The key attributes of a hashing function include:

• Always generates the same hash from the same input
• Quick to compute but not free (see proof of work)
• It is non-reversible and cannot regenerate the original message from the hash value
• A small change to the input will result in significant entropy or a change in the output
• Two different messages will never have the ...