Patent ID: 11314506

Abstract:
Provided is a secure computation device for computing a comparison operation to two integers without the use of AND/XOR. The secure computation device compares a first integer a and a second integer b when the first integer a and the second integer b, which are 0 or greater and less than 2{circumflex over ( )}k (k being an integer of 1 or greater), are subjected to ring sharing. The secure computation device includes: an addition/subtraction circuitry; a bit decomposition circuitry; and a bit extraction circuitry. The addition/subtraction circuitry uses the first integer a, the second integer b, and 2{circumflex over ( )}k to carry out a predetermined addition or subtraction with ring sharing, and output an added/subtracted result. The bit decomposition circuitry converts the added/subtracted result to bit sharing, and outputs a bit shared result. The bit extraction circuitry extracts a (k+1)-th bit of the bit shared result, and outputs an extracted result.