Patent ID: 8041050

Claim:
An audio data reproduction system which transmits an audio file taken in from a transmission-side device to a receiving-side device and reproduces the audio file received by the receiving-side device, the transmission-side device comprising: first storage means for storing audio files; file encoding means for encoding the audio files stored in the first storage means by a specific encoding method; list generation means for generating a file list of the audio files encoded by the file encoding means; list encryption means for encrypting the file list generated by the list generation means; and file transmission means for transmitting the file list encrypted by the list encryption means and the audio files encoded by the file encoding means to the receiving-side device, and the receiving-side device comprising: file receiving means for receiving the encrypted file list and encoded audio files transmitted from the transmission-side device; second storage means for storing the encrypted file list and encoded audio files received by the file receiving means; file decryption means for decrypting the encrypted file list stored in the second storage means; list determining means for determining whether the file list decrypted by the file decryption means corresponds to the encoded audio files stored in the second storage means; and file reproduction means for, if the list determining means has determined that the decrypted file list corresponds to the encoded audio files, expanding and reproducing the encoded audio files.