In　this　paper,　the　significance　of　information　security　in　the　Internet　of　Things　(IoT)　devices　is　discussed,　further　represents　various　types　of　applications　in　the　IoT　ecosystem　(smart　medical,　smart　home,　smart　transportation　etc.),　security　requirements　for　these　applications,　challenges　to　satisfy　the　requirements　of　these　applications,　diverse　types　of　cyber　security　attacks　on　the　IoT　devices,　some　useful　solutions　and　tricks　to　protect　the　IoT　ecosystem　from　intruders　and　hackers　are　also　recommended.　　©　2022　IEEE.