<P>PROBLEM TO BE SOLVED: To implement an elliptic curve pairing arithmetic effectively. <P>SOLUTION: Pairing arithmetic is implemented by pairing the following two points: a point P (Z<SB POS="POST">1</SB>=1) which is represented using an extended Inverted twisted Edward coordinate after extending the Inverted twisted Edward coordinate and is an order of prime number on a Twisted Edward-type elliptic curve; and a point Q which is represented using an affine coordinate. An encryption method by an ID-based code using the pairing arithmetic, and a decryption method to decrypt the ID-based code are provided. <P>COPYRIGHT: (C)2012,JPO&INPIT
