IBOX A     Index into SBOX     Rabbit 4000 Instruction

Opcode	Instruction	Clocks	Operation
ED 12	IBOX A	4 (2,2)	A = ibox(A)

Flags				ALTD			IOI/IOE
S	Z	L/V	C	F	R	SP	S	D
-	-	-	-		·

Description

The inverse sbox structure is a 256-byte lookup table used by the AES-128 cipher. A contains the index into the table and is replaced by the referenced value from the table.