Securing　Internet　of　Things　(IoT)　devices　in　fog　computing　systems　can　be　challenging　due　to　the　inherent　limitations　of　IoT　devices.　For　instance,　cryptographic　primitives,　such　as　attribute-based　encryption　(ABE)　schemes,　are　computationally　expensive　for　deployment　on　IoT　devices.　Thus,　ABE　is　not　realistic　in　facilitating　real-Time　updates　in　various　applications　of　IoT.　Therefore,　attribute-based　and　multi-Authority　encryption　schemes　are　designed　that　help　attribute　revocation　and　computation　outsourcing　from　IoT　devices　to　fog　computing　servers.　The　attribute　revocation　scheme　is　based　on　the　ciphertext-policy　attribute-based　encryption　(CP-ABE)　technique.　The　CP-ABE　scheme　allows　secret　keys　between　IoT　devices　and　fog　nodes　to　be　dynamically　generated　by　incorporating　the　attribute　group　keys.　Then,　the　encryption　and　decryption　functions　for　IoT　devices　are　outsourced　to　fog　nodes,　which　present　the　CP-ABE　validation.　©　2022　IEEE.