Complexity of Vulnerability-Repair Edge Deletion

Prove or refute the conjecture that finding a minimum set of edges whose removal turns a vulnerable net into a non-vulnerable net is NP-hard, and, if the conjecture holds, develop approximation algorithms for this optimization problem.

Background

The paper identifies an optimization problem complementary to vulnerability recognition: given a vulnerable net, remove as few edges as possible so that the resulting net is non-vulnerable. The authors explicitly conjecture NP-hardness rather than proving it.

They also identify approximation algorithms as a natural direction if NP-hardness is established, making both the exact complexity classification and approximation guarantees unresolved.