Abstract: The present invention relates to a method of encryption and decryption comprises the steps of: selecting a generator and a first element of a first non abelian group, respectively, computing a first inner automorphism which is used as a first public key, and generating a second public key by using a secret key being a first integer and the first public key; expressing a plain text by a product of generator of a second non abelian group, computing a second inner automorphism by using an arbitrary second integer and the first public key, computing a third inner automorphism by using the second integer and the second public key, and generating a ciphertext by using the third inner automorphism; and generating a fourth inner automorphism by using the secret key and the second inner automorphism, and decrypting the ciphertext by using the fourth inner automorphism.

Abstract: Disclosed is a spatial image information method and system for rapid and efficient storage in a relation type database and retrieval and management of spatial images acquired by a combined system of a global positioning system (GPS), an inertial navigation system (INS), and an image acquisition device (i.e., CCD camera). The spatial image acquired by the GPS/INS/CCD camera combined system is combined with an exterior orientation composed of a camera position (x,y,z), accelerated velocity, slope and direction at the moment the image is acquired and an interior orientation acquired by a camera calibration, so that calculation of a specified spatial coordinate information becomes possible.