One　of　the　significant　challenges　in　the　Internet　of　Things　(IoT)　is　the　provisioning　of　guaranteed　security　and　privacy,　considering　the　fact　that　IoT　devices　are　resource-limited.　Oftentimes,　in　IoT　applications,　remote　users　need　to　obtain　real-time　data,　with　guaranteed　security　and　privacy,　from　resource-limited　network　nodes　through　the　public　Internet.　For　this　purpose,　the　users　need　to　establish　a　secure　link　with　the　network　nodes.　Though　the　IPv6　over　low-power　wireless　personal　area　networks　(6LoWPAN)　adaptation　layer　standard　offers　IPv6　compatibility　for　resource-limited　wireless　networks,　the　fundamental　6LoWPAN　structure　ignores　security　and　privacy　characteristics.　Thus,　there　is　a　pressing　need　to　design　a　resource-efficient　authenticated　key　exchange　(AKE)　scheme　for　ensuring　secure　communication　in　6LoWPAN-based　resource-limited　networks.　This　paper　proposes　a　resource-efficient　secure　remote　user　authentication　scheme　for　6LoWPAN-based　IoT　networks,　called　SRUA-IoT.　SRUA-IoT　achieves　the　authentication　of　remote　users　and　enables　the　users　and　network　entities　to　establish　private　session　keys　between　themselves　for　indecipherable　communication.　To　this　end,　SRUA-IoT　uses　a　secure　hash　algorithm,　exclusive-OR　operation,　and　symmetric　encryption　primitive.　We　prove　through　informal　security　analysis　that　SRUA-IoT　is　secured　against　a　variety　of　malicious　attacks.　We　also　prove　the　security　strength　of　SRUA-IoT　through　formal　security　analysis　conducted　by　employing　the　random　oracle　model.　Additionally,　we　prove　through　Scyther-based　validation　that　SRUA-IoT　is　resilient　against　various　attacks.　Likewise,　we　demonstrate　that　SRUA-IoT　reduces　the　computational　cost　of　the　nodes　and　communication　overheads　of　the　network.