Contents data, recording medium, recording method and device, reproducing method and device

摘要

Content data or a record medium composed of an encrypted data portion and a plain data portion, the encrypted data portion being composed of data of a content that has been encrypted, additional information data being embedded to the plain data portion, the additional information data containing information used for decrypting the data of the content that has been encrypted, the plain data portion being read before the encrypted data portion.