Minimum security is designed to unauthorized external activity: detect and impede some detect and impede all impede some impede all

Minimum security is designed to impede and detect some unauthorized external activity. 

Using minimum security to to detect and stop some unauthorized activity often is less costly because a company or organization is using the lowest amount of security to stop outside activity. They aren't wanting to take it to the extreme with protection but in the same turn, want to be protected against unwanted items. 

Sorry wish i could