Design Space Exploration for High-Speed Implementation of the MISTY1 Block Cipher

Table 1

Logic formulation for S9 s-boxes as S9-1, S9-2, and S9-3.

yi	S9-I	Logic expressions
y9	S9-1	x9x5⊕x9x4⊕x8x4
y8		x9x7⊕x6⊕x8x6⊕x7x6
y7		x9x8⊕x8x6⊕x5⊕x9x5⊕x7x5⊕x6x5
y6		x9⊕x8x7⊕x7x5⊕x7x1⊕x5x1
y5		x9x6⊕x7x6⊕x9x4⊕x3⊕x6x4⊕x4x3⊕x7x3
y4		x9x6⊕x8x5⊕x8x3⊕x6x5⊕x5x3
y3		x9x8⊕x8x5⊕x9x1⊕x6⊕x5x1⊕x1
y2		x9x8⊕x8⊕x9x5⊕x9x2⊕x5x2
y1		x9⊕x9x8⊕x9x4⊕x9x2⊕x9x1
y9	S9-2	x8x3⊕x7x3⊕x7x2⊕1
y8		x9x3⊕x7x3⊕x9x1⊕1
y7		x9x3⊕x5x4⊕x4x3⊕x1
y6		x8x4⊕x8x2⊕x6x4⊕x5x4⊕x4
y5		x5x3⊕x3x2⊕x2x1
y4		x6x2⊕x4x2⊕x3x2⊕x2
y3		x7x4⊕x7x2⊕x5x4⊕x4x2
y2		x8x7⊕x7x6⊕x8x3⊕x8x1⊕x6x3
y1		x8x7⊕x7x4⊕x4x3
y9	S9-3	x6x2⊕x6x1⊕x5x1
y8		x6x5⊕x5x4⊕x2⊕x6x1⊕x4x1
y7		x8x2⊕x6x2⊕x16
y6		x4x3⊕x3x2⊕x15
y5		x8⊕x7x1⊕x14
y4		x9x1⊕x7⊕x2x1⊕x13
y3		x3x1⊕x2x1⊕x12⊕1
y2		x4⊕x3x2⊕x11⊕1
y1		x6x3⊕x6x1⊕x5⊕x3x1⊕x10⊕1