A pre-control system to edit contents with an extended sanitizable signature

Recently we need a new copyright protection system for a UGC (User Generated Content) in CGM (Consumer Generated Media) markets, which is generally made with re-use of existing content files. In this paper, we propose a new system that enables to pre-control editing contents with a digital signature from the viewpoint of editing control. Existent sanitizable signatures, which can only delete contents, are extended, and it is feasible to set up a work of editing as alteration, deletion and insertion including permission to edit contents. Therefore a content user can edit contents within the range of creator's permission. © 2013 The Institute of Electrical Engineers of Japan.