# Tag Info

NIST FIPS 180-4 on page 13 defines the padding scheme for SHA-512 as; Suppose that the length of the message, $M$, is $\ell$ bits. Append the bit 1 to the end of the message, followed by $k$ zero bits, where $k$ is the smallest, non-negative solution to the equation $$\ell + 1 + k \equiv 896 \bmod 1024$$ So you first append 1, then calculate the ...