A content distribution system. A distribution management and unauthorized operation management device generates a one-time URL by using URL of content information specified by a user terminal and transmits the one-time URL and bandwidth information concerning the content information to the user terminal. A session control server extracts the one-time URL from a session control message transmitted from the user terminal, transmits it to the distribution management and unauthorized operation management device, and establishes a session between the content distribution server and the user terminal according to an authentication result performed by using the one-time URL transmitted from the distribution management and unauthorized operation management device and a correlation result obtained by correlating the bandwidth information contained in the session control message transmitted from the user terminal with the bandwidth information transmitted together with the authentication result from the distribution management and unauthorized operation management device.