In　the　cloud　computing　environment,　storage　is　used　for　users　to　provide　data　outsourcing　services.　After　users　outsource　data　to　the　cloud,　privacy　protection　has　become　a　key　concern.　As　far　as　we　know,　there　is　no　systematic　analysis　of　the　assured　deletion　of　cloud　storage　data　based　on　cryptography　from　the　perspective　of　having　a　third-party　key　management　center　(TKMC)　and　no　TKMC.　Our　work　focuses　on　analyzing　and　evaluating　the　finegrained,　safety,　and　performance　of　these　schemes,　and　we　also　point　out　that　researches　can　use　trusted　computing　to　securely　strengthen　TKMC　in　the　future,　making　assured　deletion　more　secure　and　reliable.