Remove base false positive/negative rates

README.md

@@ -102,10 +102,6 @@ observable_attack_steps:
 #    will be observed as inactive at a rate of x in each observation
 # Default false positive/negative rate is 0, which is assumed if none are given.
 
-# A baseline that applies to all attack steps (default 0)
-false_positive_base_rate: <rate>
-false_negative_base_rate: <rate>
-
 # Applies false positive rates per attack step (default 0)
 false_positive_rates:
   <attack step full name>: <rate>

malsim/scenario.py

@@ -42,9 +42,7 @@
     'rewards',
     'attacker_entry_points',
     'observable_attack_steps',
-    'false_positive_base_rate',
     'false_positive_rates',
-    'false_negative_base_rate',
     'false_negative_rates',
 ]
 
@@ -193,13 +191,6 @@ def apply_scenario_false_positive_and_negative_rates(
     AttackGraph either to the default value, from the base rate
     or from the specifically set rates per attack step"""
 
-    # Apply false positive/negative base rates for all nodes (default 0)
-    fp_baseline = scenario_conf.get('false_positive_base_rate', 0)
-    fn_baseline = scenario_conf.get('false_negative_base_rate', 0)
-    for node in attack_graph.nodes:
-        node.extras['false_positive_rate'] = fp_baseline
-        node.extras['false_negative_rate'] = fn_baseline
-
     # Apply false positive rates to specified attack nodes
     fp_rates_per_attackstep = scenario_conf.get('false_positive_rates')
     if fp_rates_per_attackstep:

tests/test_scenario.py

@@ -274,12 +274,11 @@ def test_load_scenario_false_positive_negative_rate():
     )
 
     # Defined in scenario file
-    fp_base_rate = 0.1
-    fn_base_rate = 0.1
     host_0_access_fp_rate = 0.2
     host_1_access_fp_rate = 0.3
     host_0_access_fn_rate = 0.4
     host_1_access_fn_rate = 0.5
+    user_3_compromise_fn_rate = 1.0
 
     for node in attack_graph.nodes:
         if node.full_name == "Host:0:access":
@@ -288,6 +287,10 @@ def test_load_scenario_false_positive_negative_rate():
         elif node.full_name == "Host:1:access":
             assert node.extras['false_positive_rate'] == host_1_access_fp_rate
             assert node.extras['false_negative_rate'] == host_1_access_fn_rate
+        elif node.full_name == "User:3:compromise":
+            assert 'false_positive_rate' not in node.extras
+            assert node.extras['false_negative_rate'] \
+                == user_3_compromise_fn_rate
         else:
-            assert node.extras['false_positive_rate'] == fp_base_rate
-            assert node.extras['false_negative_rate'] == fn_base_rate
+            assert 'false_positive_rate' not in node.extras
+            assert 'false_negative_rate' not in node.extras

tests/testdata/scenarios/traininglang_fp_fn_scenario.yml

@@ -20,10 +20,6 @@ attacker_entry_points:
 attacker_agent_class: 'BreadthFirstAttacker'
 defender_agent_class: 'KeyboardAgent'
 
-# Baseline applies to all attack steps
-false_positive_base_rate: 0.1
-false_negative_base_rate: 0.1
-
 # Specific fpr/fnr for some specific steps
 false_positive_rates:
   'Host:0:access': 0.2