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Secure Hash Algorithms (SHA)
SHA-0 is the first version of the SHA algorithm. In 2004, several weaknesses were exposed in this algorithm, resulting in the creation of a stronger version of SHA-0 called SHA-1. In 2005, an attack on SHA-1 reported that it would find a collision in fewer hashing operations.
SHA-2 was created to overcome SHA-1's vulnerabilities, and it could be implemented with a digest size of 224, 256, 384, and 512 bits. SHA-2 is a widely used standard in modern cryptographic applications. Bitcoin uses the SHA-256 variant as a hashing algorithm to solve proof-of-work puzzles.
SHA-3 is the latest family of functions with 224-, 256-, 384-, and 512-bit variants.