User authentication method using graphic otp

The present invention relates to a user authentication method using a graphic OTP capable of authenticating a user in a manner whereby when user authentication is performed through ID and password authentication, after inputting the ID of the user, the user can be authenticated by matching a key icon and a password, selected by the user, from among a plurality of images provided by a server. When the user performs authentication by matching a user key image to a hole key image through a group of rearranged images generated one time for each authentication performed, the present invention provides a GOTP authentication method with enhanced security by performing additional authentication security according to an input pattern of the user.