A method of reproducing encrypted source data and sample data stored on a storage, the sample data having same contents with a part of the encrypted source data, including the steps of: (a) reading first management information from the storage, wherein the first management information includes first additional information being used for reproducing sample data associated with the encrypted source data, and wherein the first additional information includes a start information and end information of the sample data; (b) reproducing the sample data using the first management information, the sample data being non-encrypted and read from the storage; (c) requesting decrypting information and second management information from an external device using Uniform Resource Locator information indicating a location of the external device, wherein the decrypting information is used for decrypting the encrypted source data, wherein the second management information includes second additional information being used for reproducing the encrypted source data, wherein the second additional information includes a start information and end information of the encrypted source data, wherein the decrypting information and the second management information corresponding to the encrypted source data are searched, at the external device, based on identification information assigned to the encrypted source data, wherein the URL information and the identification information are read from the storage; (d) receiving the decrypting information and the second management information corresponding to the identification information from the external device; and (e) reproducing the encrypted source data from the storage using the decrypting information and the second management information. (a) reading first management information from the storage, wherein the first management information includes first additional information being used for reproducing sample data associated with the encrypted source data, and wherein the first additional information includes a start information and end information of the sample data; (b) reproducing the sample data using the first management information, the sample data being non-encrypted and read from the storage; (c) requesting decrypting information and second management information from an external device using Uniform Resource Locator information indicating a location of the external device, wherein the decrypting information is used for decrypting the encrypted source data, wherein the second management information includes second additional information being used for reproducing the encrypted source data, wherein the second additional information includes a start information and end information of the encrypted source data, wherein the decrypting information and the second management information corresponding to the encrypted source data are searched, at the external device, based on identification information assigned to the encrypted source data, wherein the URL information and the identification information are read from the storage; (d) receiving the decrypting information and the second management information corresponding to the identification information from the external device; and (e) reproducing the encrypted source data from the storage using the decrypting information and the second management information.