Patent ID: 8214647

Claim:
A distributed information generator comprising: a check data generator generating check data corresponding to confidential information; a confidential information distributing device distribution-coding the confidential information in accordance with access structure data indicative of an access structure of a linear secret sharing scheme; and a check data distributing device distribution-coding the check data in accordance with access structure data indicative of the same access structure as the access structure in accordance with which the confidential information is distribution-coded, wherein said check data generator is: a device which is applied with elements s of confidential information data set S; and randomly selects and outputs function specifying data k for uniquely specifying elements of function set H which satisfy H_k(x)=y, wherein said function set H satisfies |{b|bεK, H_b(x_ 1 )=y, H_{b+c}(x_ 2 )=y}|/|{b|bεK, H_b(x_ 1 )=y}|<δ for arbitrary elements x_ 1 and x_ 2 of said confidential information data set S which differ from each other, and arbitrary function specifying data c of said function set H, where K designates a set of said function specifying data, and (1−δ) designates a falsity detection probability.