KEY ESTABLISHMENT METHOD AND SYSTEM USING COMMUTATIVE LINEAR FUNCTION

摘要

A method for setting a key using a commutative linear function and a system thereof are provided to set the key by each node having low storage quantity and calculation quantity by assuring end-to-end security. A set of linear functions having cumulative law and an element of a finite field as a coefficient is defined in a server and a first linear function is selected from the set, and an element is selected from a second finite field. A second linear function corresponding to each node is selected from the set, and a coupling function generated based on the first and second linear function and a value of the second linear function having the element as a factor are transmitted from the server to each corresponding node. Each node exchanges the value of the second linear function transmitted from the server, and a calculation value using the exchanged value as a factor of the coupling function is set as a shared key among nodes(S120).