A content playback apparatus prevents related content recorded on separate media that make up a virtual package from being played separately, thereby restricting playback of the content to only when the virtual package is assembled as intended by the creator, and protecting copyright of the content. A key obtaining unit obtains a second key, with use of key management information recorded on a recording medium on which related content relating to the encrypted content is also recorded. An information obtaining unit obtains the encrypted content and key generation information that relates to generation of the first key, from a source other than the recording medium. A key generation unit generates the first key with use of the second key and the obtained key generation information. A decryption unit decrypts the encrypted content with use of the first key.