-const static uint8_t r[5][5] PROGMEM = {
- { ROT_CODE( 0), ROT_CODE(36), ROT_CODE( 3), ROT_CODE(41), ROT_CODE(18) },
- { ROT_CODE( 1), ROT_CODE(44), ROT_CODE(10), ROT_CODE(45), ROT_CODE( 2) },
- { ROT_CODE(62), ROT_CODE( 6), ROT_CODE(43), ROT_CODE(15), ROT_CODE(61) },
- { ROT_CODE(28), ROT_CODE(55), ROT_CODE(25), ROT_CODE(21), ROT_CODE(56) },
- { ROT_CODE(27), ROT_CODE(20), ROT_CODE(39), ROT_CODE( 8), ROT_CODE(14) }
+#define RP_IDX(i, j) ((((2 * j + 3 * i) % 5) * 5 + i) * 8)
+
+uint8_t const rho_pi_idx_table[5][5] PROGMEM = {
+ { RP_IDX(0, 0), RP_IDX(0, 1), RP_IDX(0, 2), RP_IDX(0, 3), RP_IDX(0, 4) },
+ { RP_IDX(1, 0), RP_IDX(1, 1), RP_IDX(1, 2), RP_IDX(1, 3), RP_IDX(1, 4) },
+ { RP_IDX(2, 0), RP_IDX(2, 1), RP_IDX(2, 2), RP_IDX(2, 3), RP_IDX(2, 4) },
+ { RP_IDX(3, 0), RP_IDX(3, 1), RP_IDX(3, 2), RP_IDX(3, 3), RP_IDX(3, 4) },
+ { RP_IDX(4, 0), RP_IDX(4, 1), RP_IDX(4, 2), RP_IDX(4, 3), RP_IDX(4, 4) }
+};
+
+#define ROT_BIT(a) (( (a) <= 4) ? ((a) << 1) : (0x01 | ((8 - (a)) << 1)))
+#define ROT_CODE(a) ((((a) / 8 + ((((a) % 8) > 4) ? 1 : 0)) << 4) | ROT_BIT(((a) % 8)))
+
+const uint8_t keccak_rotate_codes[5][5] PROGMEM = {
+ { ROT_CODE( 0), ROT_CODE( 1), ROT_CODE(62), ROT_CODE(28), ROT_CODE(27) },
+ { ROT_CODE(36), ROT_CODE(44), ROT_CODE( 6), ROT_CODE(55), ROT_CODE(20) },
+ { ROT_CODE( 3), ROT_CODE(10), ROT_CODE(43), ROT_CODE(25), ROT_CODE(39) },
+ { ROT_CODE(41), ROT_CODE(45), ROT_CODE(15), ROT_CODE(21), ROT_CODE( 8) },
+ { ROT_CODE(18), ROT_CODE( 2), ROT_CODE(61), ROT_CODE(56), ROT_CODE(14) }