SECRET TAMPERING DETECTION SYSTEM, SECRET TAMPERING DETECTION APPARATUS, SECRET TAMPERING DETECTION METHOD, AND PROGRAM

摘要

To detect tampering in secure computation while maintaining confidentiality with a little communication traffic. A random number generation part (11) generates [→ri], [→si]. A random number multiplication part (12) computes [→ti]:=[→ri→si]. A secret multiplication part (13) computes [→z]:=[→x→y], A random number verification part (14) discloses a pij-th element of each of [→ri], [→si], [→ti] and confirms whether the element has integrity as multiplication. A random number substitution part (15) randomly substitutes elements in each of [→ri], [→si], [→ti] except for the pij-th element to generate [→r'i], [→s'i], [→t'i]. A subtraction value disclosure part (16) computes [→x-→r'i], [→y-→s'i], A verification value computing part (17) computes [→ci]:=[→z]-(→x-→r'i) [→y]-(→y-→s'i) [→r'i]-[→t'i]. A verification value confirmation part (18) confirms that verification values ciare all zero.