Internet　of　Things　(IoT)　is　a　promising　technology　to　provide　product　traceability　for　industrial　systems.　By　using　sensing　and　networking　techniques,　an　IoT-enabled　industrial　system　enables　its　participants　to　efficiently　track　products　and　record　their　status　during　production　process.　Current　industrial　IoT　systems　lack　a　unified　product　data　sharing　service,　which　prevents　the　participants　from　acquiring　trusted　traceability　of　products.　Using　emerging　blockchain　technology　to　build　such　a　service　is　a　promising　direction.　However,　directly　storing　product　data　on　blockchain　incurs　in　efficiency　and　privacy　issues　in　data　management　due　to　its　distributed　infrastructure.　In　response,　we　propose　Cpds,　a　compressed　and　private　data　sharing　framework,　that　provides　efficient　and　private　data　management　for　product　data　stored　on　the　blockchain.　Cpds　devises　two　new　mechanisms　to　store　compressed　and　policy-enforced　product　data　on　the　blockchain.　As　a　result,　multiple　industrial　participants　can　efficiently　share　product　data　with　fine-grained　access　control　in　a　distributed　environment　without　relying　on　a　trusted　intermediary.　We　conduct　extensive　empirical　studies　and　demonstrate　the　feasibility　of　Cpds　in　improving　the　efficiency　and　security　protection　of　product　data　storage　on　the　blockchain.　©　2005-2012　IEEE.