| 摘要 |
PURPOSE: A Montgomery typed modular multiplier and a method thereof are provided to make the modular multiplier for fast encryption/decryption and an electronic signature has a small number of gates and use a small power. CONSTITUTION: The device includes a recording logic(110), the first CSA(Carry Save Adder)(120), a quotient logic(130), a selector(140), the second CSA(150), a full adder(160), and a CPA(Carry Propagation Adder). The recording logic performs the Booth recording for the lower 2 bits of a bit row generated by sequentially shifting the bit of a multiplier, and output a Booth recording result and the binary numbers multiplexing a multiplicand. The quotient logic receives the carry values from the first CSA, the sums output from the lower 2 full adders selected from the sum values, and the carry value output from the lower 1 full adder, and outputs a 3-bit decision value for deciding a multiple of the modular decrease. The selector selects/outputs one modular number from a set of the modular numbers preset by the decision value. |
