Patent ID: 7397920

Claim:
An information processing device, comprising: an input/output device operable to send and receive data by using a standard digital interface format; an encoder operable to encode the data to be sent; a decoder operable to decode the received data when the received data is encrypted data; a judging unit operable to judge: (i) whether said received data conforms to a IEC60958 standard so as to be audio data, (ii) whether said received data is the encrypted data, and (iii) when said received data is the encrypted data, whether said encrypted data has been properly decoded; and means operable to execute mute processing to prevent sound emission when said judging unit determines if any one of the following two items exists: (i) said received data does not conform to the IEC60958 standard, and (ii) said encrypted data has not been properly decoded when said received data is judged to be the encrypted data, and to not execute mute processing when said judging unit does not determine if any one of the two items exists, in which said received data has a number of isochronous packets; in which said judging unit is operable to judge whether said received data conforms to the IEC60958 standard so as to be audio data by utilizing data in a format ID portion of a CIP header portion of an isochronous packet of said received data, and in which said judging unit is operable to judge whether said received data is the encrypted data by utilizing data in a synchronization portion of the isochronous packet header of the isochronous packet of said received data.