Concealment calculation device, concealment calculation method and concealment calculation program

摘要

PROBLEM TO BE SOLVED: To provide a secret calculation device, a secret calculation method and a secret calculation program capable of performing secret calculation of a two-variable function in a general-purpose and high-speed manner. SOLUTION: A concealment computing device 1 has a storage unit 20 that stores a coefficient of a first polymorphic that defines a function value corresponding to the first variable by polymorphic interpolation when the second variable of a two-variable function is a constant. , The input unit 11 that accepts the input of the first ciphertext and the second ciphertext, the secret power calculation unit 12 that calculates the power of the first ciphertext, and the second variable fixed to one of the constants. 0 when the secret function calculation unit 13 that calculates the value of the first ciphertext differs from the unencrypted plain text and the constant of the second ciphertext by the inner product of the coefficient of the first ciphertext and the power of the first ciphertext. The calculation result by the secret function calculation unit 13 for each constant that the second variable can take, and the calculation result by the secret function calculation unit 14 that calculates the determination value to be a ciphertext. It includes an output unit 15 that sums up the products and outputs the value of the two-variable function. [Selection diagram] Fig. 1