57 out of 80 rounds of SHA-512, and 52 out of 64 rounds for SHA-256. Pseudo-collision bitcoin sha 2 certificate against up to 46 rounds of SHA-256.
For example, computing the hash of a downloaded file and comparing the result to a previously published hash result can show whether the download has been modified or tampered with. SHA-256 and SHA-512 are novel hash functions computed with 32-bit and 64-bit words, respectively. They use different shift amounts and additive constants, but their structures are otherwise virtually identical, differing only in the number of rounds. SHA-224 and SHA-384 are simply truncated versions of the first two, computed with different initial values. The SHA-2 family of algorithms are patented in US patent 6829355. 46 out of 64 rounds of SHA-256. 256 instead of SHA-224 and SHA-256.
This also happens to be faster than SHA-224 and SHA-256 on x86-64, since SHA-512 works on 64 bit instead of 32 bit words. One iteration in a SHA-2 family compression function. The bitwise rotation uses different constants for SHA-512. The given numbers are for SHA-256. With the publication of FIPS PUB 180-2, NIST added three additional hash functions in the SHA family. The algorithms were first published in 2001 in the draft FIPS PUB 180-2, at which time public review and comments were accepted. FIPS PUB 180-1, which was released in April 1995.
The updated standard included the original SHA-1 algorithm, with updated technical notation consistent with that describing the inner workings of the SHA-2 family. In October 2008, the standard was updated in FIPS PUB 180-3, including SHA-224 from the change notice, but otherwise making no fundamental changes to the standard. The primary motivation for updating the standard was relocating security information about the hash algorithms and recommendations for their use to Special Publications 800-107 and 800-57. Detailed test data and example message digests were also removed from the standard, and provided as separate documents. 256, and describing a method for generating initial values for truncated versions of SHA-512. Additionally, a restriction on padding the input data prior to hash calculation was removed, allowing hash data to be calculated simultaneously with content generation, such as a real-time video or audio feed.
Padding the final data block must still occur prior to hash output. In July 2012, NIST revised SP800-57, which provides guidance for cryptographic key management. The publication disallows creation of digital signatures with a hash security lower than 112-bits after 2013. The previous revision from 2007 specified the cutoff to be the end of 2010. In August 2012, NIST revised SP800-107 in the same manner. The SHA-3 algorithm is not derived from SHA-2.