| 摘要 |
<p>A system and method is provided for using a general purpose processor to implement permutation and/or round opcodes for encrypting and/or decrypting data in accordance with the data encryption standard (DES) algorithm. In one embodiment of the present invention, an encryption unit is adapted to implement a permutation (or rotation) function on a first operand obtained from a general purpose register, where the permutation function is derived from a permutation opcode and a second operand provided to the encryption unit. In this embodiment, the permutation opcode is used to instruct the encryption unit to perform a permutation function, and the second operand is used to delineate which permutation function is to be performed. In another embodiment of the present invention, the encryption unit is adapted to implement a round function on two operands obtained from general purpose registers. In this embodiment a round opcode is used to instruct the encryption unit to perform the round function. In another embodiment, the encryption unit is adapted to perform the round function by implementing four permutation and two exclusive-or functions.</p> |
