Unintentional vs. intentional impacts No impact strategy Attacker’s strategy maximizing the expected damage

Basic Definitions lowest-level part of system, which is characterized by its inherent value, availability and performance distribution collection of elements with the same functionality connected in parallel in reliability logic-diagram sense quantitative measure of task performing intensity of element or system (capacity, productivity, processing speed, task completion time etc.)

Basic Definitions technical or organizational measure aimed at reduction of destruction probability of a group of system elements in the case of attack action aimed at preventing simultaneous destruction of several elements in the case of single attack (can be performed by spatial dispersion, by encapsulating different elements into different protective casings, by using different power sources etc.) group of system elements separated from other elements (and possibly protected) so that a single external impact destroying elements belonging to a certain group cannot destroy elements from other groups object that imitates protected group of system elements, but does not contain any element (the total damage caused by the destruction of any false target is much lower than the damage caused by the destruction of any protection group)

Defense strategy Damage Separation Protection Destruction probability False targets Impact probability Disinformation p g v

Defense Strategy  F dF Defense Strategy Cost

Expected damage model Cumulative performance of the group Attack probabilityProtection vulnerability System performance reduction Equipment losses Expected damage Failures p v g Functional losses

Expected Damage Cost Unsupplied demand Loss of demand

Expected Damage Cost Destruction of false targets System destruction Protections and infrastructure Elements Functional losses Optimal defense strategy Limited defense budgetUnlimited defense budget

Single attack strategy Perfect knowledge about the system No knowledge about the system p=1/N p=1 p Imperfect knowledge about the system pp  p i =1

Multiple attack strategy Unlimited resource p=1 ppp Limited resource + perfect knowledge about the system p=1 Limited resource + imperfect knowledge about the system  p i >1

Attacker’s Strategy Single Attack Perfect attacker’s knowledge about the system Multiple Attacks

Attacker’s Strategy Single Attack No knowledge about the system Multiple Attacks Limited resource (E attacks) Unlimited resource Imperfect knowledge about the system