Every work has limitations. Some inherits from the design; Some exist because they are just obvious but complex to implement. Reviewers might be interested in this to see how you understand the solution by yourself. Some reviewers will reject you if they pointed out some limitations that you haven’t discussed in the paper. However, if you can discuss the limitation of your work thoroughly, this will show the depth of your understanding in the field and will get your work be understood better.
As a security solution for a computer system, here are some factors can be easily forgotten but might be important to discuss:
Reference 1
If you could revise
the fundmental principles of
computer system design
to improve security...
... what would you change?