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Factor Overview

FactorField IDRisksheet HeaderEnum IDValuesScore Range
Elapsed TimeattackTimeTIMEtaraRecord-attackTime50-19
Specialist ExpertiseattackExpertiseEXPtaraRecord-attackExpertise40-8
Knowledge of ItemattackKnowledgeKNOWtaraRecord-attackKnowledge40-11
Window of OpportunityattackWooWOOtaraRecord-attackWoo40-10
EquipmentattackEquipmentEQPtaraRecord-attackEquipment40-9
All five factors appear in the Risksheet 2. Assess Feasibility view under the Attack Feasibility column group (blue: rgba(96, 172, 238, 0.12)). Maximum possible aggregate score: 19 + 8 + 11 + 10 + 9 = 57

Elapsed Time (attackTime)

Rates the time required to complete the attack. Higher time requirements reduce feasibility. Source: .polarion/tracker/fields/taraRecord-attackTime-enum.xml
Enum IDLabelScoreDescription
lte1d<= 1 day0Attack completable within one day. Highest feasibility contribution.
lte1w<= 1 week1Attack requires up to one week.
lte1mo<= 1 month4Attack requires up to one month. Mid-range threshold.
lte6mo<= 6 months17Attack requires up to six months. APT-class timelines.
gt6mo> 6 months19Attack requires more than six months. Lowest feasibility contribution.

Specialist Expertise (attackExpertise)

Rates the level of specialist security knowledge required by the attacker. Source: .polarion/tracker/fields/taraRecord-attackExpertise-enum.xml
Enum IDLabelScoreDescription
laymanLayman0No specific security knowledge required.
proficientProficient3Familiarity with product security behavior required. Product-level knowledge.
expertExpert6Understanding of algorithms, cryptographic protocols, or internal security mechanisms required.
multipleExpertsMultiple Experts8Coordinated expertise across multiple security disciplines required (e.g., hardware + cryptography + network). Team attack.

Knowledge of Item (attackKnowledge)

Rates the confidentiality level of information required to execute the attack. Source: .polarion/tracker/fields/taraRecord-attackKnowledge-enum.xml
Enum IDLabelScoreDescription
publicPublic0Information is publicly available (e.g., published CVEs, public documentation).
restrictedRestricted3Information is restricted to specific teams or organizations. Requires industry-specific access.
confidentialConfidential7Information is shared on a need-to-know basis within the organization.
strictlyConfidentialStrictly Confidential11Information is known only to a very small number of individuals with highest clearance.

Window of Opportunity (attackWoo)

Rates how accessible the attack surface is to the attacker. “WOO” is the EVITA abbreviation for Window of Opportunity. Source: .polarion/tracker/fields/taraRecord-attackWoo-enum.xml
Enum IDLabelScoreDescription
unlimitedUnlimited0Attack surface always accessible. No time constraint. Highest feasibility.
easyEasy1Extended access without detection risk. Low barrier.
moderateModerate4Limited time window or moderate access privileges required.
difficultDifficult10Very narrow time window AND insider-level privileges required. Both constraints must apply.

Equipment (attackEquipment)

Rates the sophistication of tools required to execute the attack. Source: .polarion/tracker/fields/taraRecord-attackEquipment-enum.xml
Enum IDLabelScoreDescription
standardStandard0Readily available tools (standard PC, public software).
specializedSpecialized4Specialized non-commodity tools (e.g., JTAG hardware debugger).
bespokeBespoke7Custom-built non-commercial equipment. Well-resourced adversary required.
multBespokeMultiple Bespoke9Multiple distinct custom-built tools required. Most restricted attacker population.

Score Aggregation

The Risksheet feasibilityFormula sums all five factor scores:
aggregate_score = attackTime + attackExpertise + attackKnowledge + attackWoo + attackEquipment
The aggregate score maps to a TARA Feasibility Level:
Aggregate ScoreFeasibility Level
0 - 13High (easy to attack)
14 - 19Medium
20 - 24Low
25+Very Low (hard to attack)

Scoring Example

FactorSelectionScore
Elapsed Time<= 1 week1
ExpertiseProficient3
KnowledgeRestricted3
Window of OpportunityEasy1
EquipmentStandard0
Total8
FeasibilityHigh (8 <= 13)

Risksheet Column Configuration

All five factor columns share these properties:
PropertyValue
Level5 (Threat Path level)
GroupAttack Feasibility
Group Colorrgba(96, 172, 238, 0.12) (blue)
View2. Assess Feasibility
Read-Only in FormYes (editable only in Risksheet)