Abstract:
PURPOSE: A subtraction operation device for a Montgomery inverse algorithm and a method thereof are provided to perform a complementary operation and an add operation based on two variables, thereby comparing and operating sizes at the same time. CONSTITUTION: A comparison operation unit (110) compares the sizes of variable U and variable V. A subtraction operation unit (120) operates a difference value of the variable U and the variable V by performing an add operation with the complement of the bit values for the variable U and the variable V. The comparison operation unit compares the sizes of the variable U and the variable V by considering the most significant bit value of a reference value. When the most significant bit value is 1, the comparison operation unit determines that the variable U is bigger than the variable V. [Reference numerals] (110) Comparison operation unit; (120) Subtraction operation unit; (AA) Variable U; (BB) Variable V
Abstract:
PURPOSE: A modular multiplication device for a password and a method are provided to repetitively perform a twice modulus operation and an add modulus operation, thereby implementing an elliptic curve on a finite field. CONSTITUTION: A coefficient selection unit (110) extracts a coefficient for each bit order for a multiplier from two elements. A twice modulus operation unit (120) performs a first twice modulus operation for a multiplication operation result for a most significant n-bit coefficient and a multiplicand. An add modulus operation unit (130) performs a first add modulus operation for a multiplication operation result for a (n-1) bit coefficient and the multiplicand. A control unit (140) repetitively performs the first twice modulus operation and the first add modulus operation for a lower bit coefficient and the multiplicand. [Reference numerals] (110) Coefficient selection unit; (120) Twice modulus operation unit; (130) Add modulus operation unit; (140) Control unit; (AA) Atom B; (BB) Atom A