Patent US 7,979,712

A method, apparatus and system to ensure the security in the information exchange and to provide list matching with higher efficiency and practicality. In a particular embodiment, each of lists to be subject to list matching is represented as a polynomial having roots equivalent to the items of the list. Then, polynomials generated for the lists to be subject to list matching are added according to a distributed secret computation. A list containing an item equivalent to a root of a polynomial resulting from the addition is created and output as the list of a common item.