In　order　to　solve　the　problem　between　low　power　of　Internet　of　Things　devices　and　the　high　cost　of　cryptography,　lightweight　cryptography　is　required.　The　improvement　of　the　scalar　multiplication　can　effectively　reduce　the　complexity　of　elliptic　curve　cryptography　(ECC).　In　this　paper,　we　propose　a　fast　formula　for　point　septupling　on　elliptic　curves　over　binary　fields　using　division　polynomial　and　multiplexing　of　intermediate　values　to　accelerate　the　computation　by　more　than　14%.　We　also　propose　a　scalar　multiplication　algorithm　based　on　the　step　multi-base　representation　using　point　halving　and　the　septuple　formula　we　proposed,　which　significantly　reduces　the　computational　cost.　The　experimental　results　show　that　our　method　is　more　efficient　over　binary　fields　and　contributes　to　reducing　the　complexity　of　ECC.