Patent ID: 7239703
Filing Date: 2007-07-03
Classification: H04L,H04N

Abstract:
1. A method of recording digital data that may be authenticated into a recording medium in a recording format, the method comprising the steps of: recording in advance a first value into the recording medium in the recording format as data that cannot be output as a playback signal from a playback apparatus used for the recording medium; and recording content data prepared to be played back, sync data and a second value into the recording medium in the recording format as the digital data that may be output as playback signals from the playback apparatus; wherein the second value is placed at a position apart from the sync data by a first distance, a portion of the content data having a length of a predetermined number of bits is placed at a position apart from the sync data by a second distance, a value of an authenticator is determined according to a predetermined formula from the first value, the portion of the content data and the second value, and the second value is set so as to have the value of the authenticator equal a predetermined value.