Selecting optimal subset of security controls

Choosing an optimal investment in information security is an issue most companies face these days. Which security controls to buy to protect the IT system of a company in the best way? Selecting a subset of security controls among many available ones can be seen as a resource allocation problem that should take into account conflicting objectives and constraints of the problem. In particular, the security of the system should be improved without hindering productivity, under a limited budget for buying controls. In this work, we provide several possible formulations of security controls subset selection problem as a portfolio optimization, which is well known in financial management. We propose approaches to solve them using existing single and multiobjective optimization algorithms.