Originally designed by the US Government’s National Security Agency in 2001, and released under a royalty-free licence, SHA is considered one of the most digitally secure ways to encrypt and protect information. It is used by Bitcoin as the basis of its Proof of Work algorithm, a variation of the Hashcash function invented by British cryptographer Adam Back in 1997. It’s also used in creating Bitcoin addresses, thereby improving security and privacy. It is estimated there are as many solutions to SHA 256 as there are grains of sand on earth, making the economics of trying to crack it using brute force techniques unviable. See the section on ‘Proof of Work’ to learn more about the fundamentals of its application to blockchain technology.