I’m trying to calculate the constants used for the SHA512 hash. But each iteration removes four hex digits and I’m not sure why. Any help or advice is appreciated! Let me know if something isn’t clear, and I’ll do my best to explain it better.

The first one is `428a2f98d728ae22`

. It can be found by taking the **cube root** of `2`

. Getting the mantissa/significand (ref:wikipedia). Then multiplying that by `16`

. This would give you `4`

, the first digit of the hex digit at the beginning of this paragraph. You then do this repeatedly until you’ve processed the first 64 bits.

These words represent the first sixty-four bits of the fractional parts of the cube roots of the first eighty prime numbers. In hex, these constant words are (from left to right)

Ref: FIPS 180-2.