As　an　essential　component　of　cloud　computing,　cloud　storage　provides　flexible　data　storage　services　for　individuals　and　organizations.　By　storing　multiple　replicas　of　data　in　servers,　cloud　storage　providers　(CSPs)　can　improve　availability　and　stability　of　the　cloud　storage　service.　To　ensure　that　all　data　replicas　of　a　cloud　user　are　intact　and　completely　stored　in　the　CSP,　many　multi-replica　cloud　auditing　schemes　have　been　proposed.　However,　such　schemes　are　predominantly　based　on　the　public　key　infrastructure　(PKI),　which　incurs　complex　certificate　management.　In　addition,　existing　schemes　do　not　consider　support　for　sector-level　dynamic　auditing.　In　this　paper,　we　propose　a　fine-grained　dynamic　multi-replica　data　auditing　scheme　that　has　the　following　features:　(1)　it　uses　ID-based　cryptography　to　eliminate　the　cost　of　certificate　management,　(2)　it　supports　efficient　sector-level　dynamic　operations　on　cloud　user　data,　and　(3)　it　optimizes　the　challenge　algorithm　to　reduce　the　computational　cost　of　the　third　party　auditor　(TPA).　We　show　that　the　proposed　scheme　is　provably　secure　based　on　a　random　oracle　model.　The　performance　analysis　and　experiments　show　the　efficiency　of　the　proposed　scheme.