| Existing Studies | Consolidated Introduction | Illustration of threats and issues at the layers of IoT | Examples of Security and privacy attacks | In-depth research on security Requirements | Suggestions for future directions |
| [9] | ✓ | ✓ | ✓ |
| ✓ |
| [11] | ✓ |
|
| ✓ | ✓ |
| [12] | ✓ | ✓ | ✓ | ✓ |
|
| [13] | ✓ |
| ✓ |
| ✓ |
| [14] | ✓ |
| ✓ |
| ✓ |
| [15] | ✓ | ✓ |
| ✓ | ✓ |
| This work | ✓ | ✓ | ✓ | ✓ | ✓ |