SHA-256 block compression

NSA / NIST (FIPS 180 family), 1995

The Secure Hash Algorithm family was released by NIST in 1993 (SHA-0) with revisions leading to SHA-1 and the SHA-2 suite including SHA-256 (2001 publication, building on Merkle–Damgård block compression). This exhibit animates the dataflow shape—sixteen block words, cube-root round constants, an expanding schedule, and eight working registers—without performing bitwise-accurate compression.