SHA-3

SHA-3 (Secure Hash Algorithm 3) is the latest member of the Secure Hash Algorithm family of standards, released by the National Institute of Standards and Technology (NIST) in 2015. SHA-3 was developed as a part of a public competition to create a new hash algorithm that would be more resistant to the types of attacks that had started to threaten its predecessors like SHA-1 and SHA-2.

SHA-3 can produce hash values of different lengths – 224, 256, 384, or 512 bits, making it versatile for various security requirements. It offers strong resistance against known types of cryptographic attacks, including the ones that have started to affect SHA-1 and SHA-2 (like collision attacks).

SHA-3 uses a mathematical model known as "sponge construction," which differs from the Merkle-Damgård construction used in previous SHA versions. This construction allows SHA-3 to have flexibility in terms of input and output lengths and makes it suitable for a variety of cryptographic applications beyond just hashing.

Despite being a part of the SHA family, SHA-3 is not derived from its predecessors and uses a unique design approach.

Like other hash functions, SHA-3 is used to ensure the integrity of data in various information security applications. It is employed in digital signature algorithms to verify the authenticity and integrity of messages. Some cryptocurrencies use SHA-3 or its variants for added security.

While SHA-3 is not intended to replace SHA-2 (which is still considered secure), it provides an alternative in the cryptographic toolkit. The development of SHA-3 is more about having a diversity of secure options available than about SHA-2 being inadequate.

An example of a SHA-3 hash of the string "Hello, world!" with a 256-bit output might look something like this (though the actual output can vary based on specific implementation details):

a7ffc6f8bf1ed76651c14756a061d662f580ff4de43b49fa82d80a4b80f8434a