An information processing device includes a data processing unit executing decryption and playing processing of an encrypted content, with the data processing unit executing content playback propriety determination processing by applying an encrypted content signature file set in response to a content to be played; with the encrypted content signature file including a content hash list group including a hash value, and signature data for data generated from a content encryption key and the content hash list group; and with the data processing unit executing, with the content playback propriety determination processing, hash value matching processing between a hash value calculated from a content to be played, and a hash value for matching included in the content hash list group, and signature data verification processing to which the signature has been applied to perform decryption and playing processing of the encrypted content with success of both processes as a condition.