In　this　article,　we　propose　dual　traceable　distributed　attribute　based　encryption　with　subset　keyword　search　system　(DT-DABE-SKS,　abbreviated　as　DT)　to　simultaneously　realize　data　source　trace　(secure　provenance)　and　user　trace　(traitor　trace)　and　flexible　subset　keyword　search　from　polynomial　interpolation.　Leveraging　non-interactive　zero-knowledge　proof　technology,　DT　preserves　privacy　for　both　data　providers　and　users　in　normal　circumstances,　but　a　trusted　authority　can　disclose　their　real　identities　if　necessary,　such　as　the　providers　deceitfully　uploading　false　data　or　users　maliciously　leaking　secret　attribute　key.　Next,　we　introduce　the　new　conception　of　updatable　and　transferable　message-lock　encryption　(UT-MLE)　for　block-level　dynamic　encrypted　file　update,　where　the　owner　does　not　have　to　download　the　whole　ciphertext,　decrypt,　re-encrypt　and　upload　for　minor　document　modifications.　In　addition,　the　owner　is　permitted　to　transfer　file　ownership　to　other　system　customers　with　efficient　computation　in　an　authenticated　manner.　A　nontrivial　integration　of　DT　and　UT-MLE　lead　to　the　distributed　ABSE　with　ownership　transfer　system　(DTOT)　to　enjoy　the　above　merits.　We　formally　define　DT,　UT-MLE,　and　their　security　model.　Then,　the　instantiations　of　DT　and　UT-MLE,　and　the　formal　security　proof　are　presented.　Comprehensive　comparison　and　experimental　analysis　based　on　real　dataset　affirm　their　feasibility.　©　2013　IEEE.