Voir la source de SHA-2

===== Constantes =====
SHA-256 utilise 64 valeurs constantes de mots de 32 bits, notés <math>K^{\{256\}}_0, K^{\{256\}}_1, ..., K^{\{256\}}_{63}~</math>. ces nombres représentent les 32 premiers bits de la partie décimale des racines cubiques des 64 premiers [[Nombre premier|nombres premiers]]. Les valeurs suivantes sont exprimées en notation hexadécimale (base 16).

{|class="wikitable" style="font-family:monospace;font-size:120%;line-height:normal"
|-
! <math>K^{\{256\}}_{0}, ..., K^{\{256\}}_{7}</math>
| 0x428a2f98 || 0x71374491 || 0xb5c0fbcf || 0xe9b5dba5 || 0x3956c25b || 0x59f111f1 || 0x923f82a4 || 0xab1c5ed5
|-
! <math>K^{\{256\}}_{8}, ..., K^{\{256\}}_{15}</math>
| 0xd807aa98 || 0x12835b01 || 0x243185be || 0x550c7dc3 || 0x72be5d74 || 0x80deb1fe || 0x9bdc06a7 || 0xc19bf174
|-
! <math>K^{\{256\}}_{16}, ..., K^{\{256\}}_{23}</math>
| 0xe49b69c1 || 0xefbe4786 || 0x0fc19dc6 || 0x240ca1cc || 0x2de92c6f || 0x4a7484aa || 0x5cb0a9dc || 0x76f988da
|-
! <math>K^{\{256\}}_{24}, ..., K^{\{256\}}_{31}</math>
| 0x983e5152 || 0xa831c66d || 0xb00327c8 || 0xbf597fc7 || 0xc6e00bf3 || 0xd5a79147 || 0x06ca6351 || 0x14292967
|-
! <math>K^{\{256\}}_{32}, ..., K^{\{256\}}_{39}</math>
| 0x27b70a85 || 0x2e1b2138 || 0x4d2c6dfc || 0x53380d13 || 0x650a7354 || 0x766a0abb || 0x81c2c92e || 0x92722c85
|-
! <math>K^{\{256\}}_{40}, ..., K^{\{256\}}_{47}</math>
| 0xa2bfe8a1 || 0xa81a664b || 0xc24b8b70 || 0xc76c51a3 || 0xd192e819 || 0xd6990624 || 0xf40e3585 || 0x106aa070
|-
! <math>K^{\{256\}}_{48}, ..., K^{\{256\}}_{55}</math>
| 0x19a4c116 || 0x1e376c08 || 0x2748774c || 0x34b0bcb5 || 0x391c0cb3 || 0x4ed8aa4a || 0x5b9cca4f || 0x682e6ff3
|-
! <math>K^{\{256\}}_{56}, ..., K^{\{256\}}_{63}</math>
| 0x748f82ee || 0x78a5636f || 0x84c87814 || 0x8cc70208 || 0x90befffa || 0xa4506ceb || 0xbef9a3f7 || 0xc67178f2
|}