dpia-risk-scoring

DPIA Risk Scoring Methodology

Overview

Art. 35(7)(c) GDPR requires a DPIA to include "an assessment of the risks to the rights and freedoms of data subjects." This skill provides a quantifiable risk scoring framework that converts qualitative privacy risks into comparable, prioritised scores supporting mitigation decisions.

Risk Scoring Framework

Severity Scale (Impact on Data Subject Rights)

Level	Score	Description	Examples
Negligible	1	Minor inconvenience, easily recoverable	Temporary inability to access non-essential service
Limited	2	Significant inconvenience, recoverable with effort	Targeted advertising based on inferred preferences
Significant	3	Serious consequences, difficult to recover from	Financial loss, discrimination, reputational harm
Maximum	4	Irreversible or very difficult to recover from	Identity theft, physical safety risk, loss of employment

Likelihood Scale

Level	Score	Description	Indicators
Negligible	1	Unlikely given current controls	Strong technical controls, limited access, encrypted at rest and in transit
Limited	2	Possible but requires specific conditions	Some access controls, partial encryption, known but unproven attack vectors
Significant	3	Probable given known threat landscape	Weak controls in specific areas, prior incidents in sector, active threat actors
Maximum	4	Near-certain or already occurring	No controls, known vulnerabilities, prior breach of similar system

Risk Matrix

Severity →    Negligible(1)  Limited(2)  Significant(3)  Maximum(4)
Likelihood ↓
Maximum(4)        4(M)         8(H)        12(VH)         16(VH)
Significant(3)    3(L)         6(M)         9(H)          12(VH)
Limited(2)        2(L)         4(M)         6(M)           8(H)
Negligible(1)     1(L)         2(L)         3(L)           4(M)

Risk Levels: L=Low(1-3), M=Medium(4-6), H=High(7-9), VH=Very High(10-16)

Risk Categories (ENISA-Aligned)

Rights and Freedoms Impacts

1. Loss of confidentiality -- Unauthorised disclosure of personal data
2. Loss of integrity -- Unauthorised modification of personal data
3. Loss of availability -- Inability to access or use personal data
4. Loss of purpose limitation -- Data used beyond original purpose
5. Discrimination -- Unfair treatment based on processing outcomes
6. Identity theft/fraud -- Misuse of personal data for impersonation
7. Financial loss -- Direct or indirect monetary harm
8. Reputational damage -- Social standing or professional harm
9. Physical harm -- Safety or health impacts
10. Loss of autonomy -- Chilling effects on behaviour or free expression

Inherent vs Residual Risk

• Inherent risk: Risk level before applying any mitigation measures
• Residual risk: Risk level after applying planned mitigation measures
• Risk reduction: Difference between inherent and residual risk scores
• Acceptable risk threshold: Organisation-defined tolerance level

Art. 36 Prior Consultation Trigger

When residual risk remains High or Very High after all feasible mitigation measures, the controller must consult the supervisory authority under Art. 36(1) before commencing processing.