Method and apparatus for key agreement between devices using polynomial ring

摘要

A key agreement method using a polynomial ring and an apparatus using the same are provided to use a key agreement protocol having a high processing speed in the same security level by using a small polynomial coefficient. A key agreement method using a polynomial ring includes the steps of: generating a first seed polynomial expression using polynomial expressions which are randomly selected from the polynomial ring Rq(310); transmitting the first seed polynomial expression to a second device, and receiving a second seed polynomial expression from the second device; changing the second seed polynomial expression using the polynomial expressions which are randomly selected from the polynomial ring Rq, and transmitting the changed second seed polynomial to the second device(320); receiving the changed first seed polynomial from the second device(330); and generating a sharing key using the changed first seed polynomial expression and the polynomial expressions which are randomly selected in the first seed polynomial expression step and the second seed polynomial expression change step(340).