Data nullification device for nullifying digital content recorded on a recording medium, after the digital content has been reproduced, a predetermined time period has passed since the recording of the digital content, or the digital content has been moved to another recording medium

摘要

In a data nullification device for nullifying target data recorded on a recording medium, target data is made up of a plurality of data blocks. A judging unit judges, in units of data blocks, whether the target data needs to be nullified. A nullifying unit nullifies, when a predetermined number of data blocks are judged as needing to be nullified or when one or more data blocks whose total amount of data reaches a predetermined amount are judged as needing to be nullified, the judged data blocks.