IPv6　over　Low　Power　Wireless　Personal　Area　Network　(6LoWPAN)　has　emerged　as　a　promising　1technology　to　realize　ambient　intelligence　under　the　vision　of　the　Internet　of　Things.　Under　most　circumstances,　it　is　imperative　that　security　be　addressed　from　bootstrapping　to　data　transmission.　In　this　paper,　we　propose　a　secure　bootstrapping　scheme　that　includes　mutual　authentication　and　trust　evaluation　to　provide　the　first　security　measure　for　6LoWPAN.　The　scheme　is　based　on　multi-hop　cluster-tree　hierarchical　topology　in　which　pairwise　keys　between　neighboring　nodes　and　trust　paths　to　the　base　station　(BS)　are　established　at　the　same　time.　Mutual　authentication　that　is　based　on　pairing　requires　only　the　storage　of　one　key　and　the　exchange　of　IDs　considering　the　computational　complexity　of　public　key　algorithms　and　the　frangibility　of　shared　key　protocols.　Trust　evaluation　relies　on　multiple　criteria　to　achieve　security　and　energy　efficiency　and　to　balance　the　whole　network.　The　BS　also　maintains　a　dynamic　blacklist　to　prevent　denial　of　service　(DoS)　attacks.　Analysis　shows　that　the　proposed　scheme　is　secure　and　scalable.　The　energy　cost　in　terms　of　computation　and　communication　as　well　as　storage　are　also　analyzed　and　compared　to　that　of　shared　key　protocols　and　public　key　algorithms　through　quantitative　analysis.　©　2012　ACADEMY　PUBLISHER.