While　data　sharing　cross　management　is　increasingly　popular,　there　are　challenges　in　such　a　decentralized　data　sharing　mode,　especially　in　terms　of　transaction　fairness　and　copyright　protection.　However,　few　schemes　consider　both　fairness　and　copyright　protection　in　the　current　literature.　In　this　paper,　we　propose　a　flexible　and　Ethereum-based　scheme　to　facilitate　copyright　protection　in　data　sharing　blockchain,　by　using　watermark　based　policies.　This　allows　us　to　achieve　properties　such　as　preventing　the　re-selling　of　data　(e.g.,　partial　data,　combined　data,　and　leaked　data).　We　also　design　five　algorithms　to　automatically　guarantee　data　sharing　fairness　and　proactively　protect　data　copyright,　by　using　smart　contracts.　In　other　words,　several　new　security　features　are　introduced　to　existing　transaction　schemes,　while　still　achieving　feasible　performance.　The　response　times　for　each　key　step　of　smart　contract　in　the　proposed　scheme　is　between　0.41　s　and　0.91　s.