What values can be assigned to Attack Tree leaf nodes?

Question

Accepted Answer

Any metric that quantifies an attack: boolean (possible?), cost, time, probability of success, or likelihood of attempt.
Leaf node values quantify the attack:

Value Type
What it measures
Example

Boolean
Possible vs. Impossible
Can the attacker reach this node?

Cost
Resources needed to attack
$20K to bribe an insider

Time
Duration to execute
3 days to crack password

Probability
Chance attacker will succed
80% chance of finding vuln

Likelihood
Chance attacker will try
High if target is valuable

Calculating parent node values:

OR nodes = value of their cheapest child (attacker takes easiest path)
AND nodes = sum of all children (attacker must complete all steps)

Tip: For cost analysis, OR nodes use min() (attacker picks cheapest), AND nodes use sum() (attacker pays all). This is the key to calculating root node cost.

Value Type	What it measures	Example
Boolean	Possible vs. Impossible	Can the attacker reach this node?
Cost	Resources needed to attack	$20K to bribe an insider
Time	Duration to execute	3 days to crack password
Probability	Chance attacker will succed	80% chance of finding vuln
Likelihood	Chance attacker will try	High if target is valuable