A reproducing apparatus and method are provided to reproduce an interactive content requiring authentication from a recording medium such as a disc or a remote server, via the Internet. An authenticating method employed at a remote server includes: (a) transmitting program codes for performing authentication to a reproducing apparatus in response to a request of content requiring the authentication from the reproducing apparatus; (b) receiving identification information for the authentication, which is transmitted as a result of executing the program codes in the reproducing apparatus, from the reproducing apparatus and performing the authentication; and (c) if the authentication is successful, transmitting the requested content to the reproducing apparatus, and if the authentication is not successful, transmitting a message notifying the authentication failure to the reproducing apparatus. As a result, only a function of reading data recorded on a disc according to a disc type is required without supporting a new method for disc authentication required by a content provider whenever a disc with a new format is produced or whenever a content format is developed. A reproducing apparatus can download a desired content from various servers after authentication without having to support various authenticating methods.