Security Decision Registry (SDR)
A structured model for documenting, analyzing, and learning from the security decisions that shape organizational risk
Created by Claudiu Tabac - © 2026
This material is open for educational and research use. Commercial use without explicit permission from the author is not allowed
Why Decisions Matter More Than Controls
The Traditional View
Most security narratives begin their analysis too late in the failure chain. Organizations typically start investigating after discovering a control gap, after receiving an audit finding, or after experiencing a security incident. This reactive approach focuses on symptoms rather than root causes.
The assumption is that security failures stem from missing controls, inadequate frameworks, or insufficient technology investment. But this perspective misses the critical inflection point where risk actually originates.
The Decision Layer
The Security Decision Registry starts earlier, at the point where choices are made. Security failures typically originate when risk is accepted without adequate threat context, when exceptions are approved without defining an end state, or when audit closure is mistakenly treated as risk closure.
These decisions appear individually rational at the time. They are made by competent professionals with good intentions. Yet collectively, they create dangerous exposures that compound over time and rarely get documented as risk drivers.
Core Insight: Most security failures are not caused by missing controls, but by decisions that seemed reasonable at the time and were never revisited.
What the Security Decision Registry Is
A Curated Registry
SDR documents recurring security decision patterns observed across organizations. Each pattern represents a type of choice that appears repeatedly, with predictable consequences that emerge over time.
- Decision patterns, not implementations
- Focused on reasoning structures
- Built from real organizational experience
CISO & Audit Focused
The registry addresses the realities faced by security leaders and assurance professionals. It explains why organizations fail despite having controls and maintaining compliance frameworks.
- Structured for executive context
- Bridges security and governance
- Supports strategic reasoning
A Reasoning Tool
SDR helps you understand what decision created the exposure you are now dealing with. It provides a framework for recognizing patterns before they accumulate into systemic risk.
- Enables decision analysis
- Makes risk drivers visible
- Supports pattern recognition
What SDR Is Not
Not a Framework
SDR is not a maturity model or compliance framework. It does not prescribe organizational structure or capability levels.
Not a Playbook
SDR is not a checklist or implementation guide. It does not tell you what controls to deploy or how to configure systems.
Not Vendor Guidance
SDR is not product documentation or vendor-specific guidance. It remains independent of commercial solutions and technology choices.
Not Incident Response
SDR is not incident response documentation or crisis management procedures. It addresses the decisions that precede incidents, not the response to them.
When Security Decisions Go Wrong
Security decisions fail when critical information is missing, when assumptions go unchallenged, or when organizational pressures override careful reasoning. Understanding these failure modes helps leaders recognize and prevent them.
Authority Replaces Evidence
Decisions get approved based on organizational hierarchy rather than supporting data. Senior leaders override security assessments without engaging with the underlying analysis. The decision becomes final because of who made it, not because the reasoning was sound.
Urgency Replaces Reasoning
Business pressure accelerates decisions past the point of adequate analysis. "We need to launch Monday" becomes justification for skipping security review. The timeline drives the decision rather than the risk profile.
Exceptions Without End States
Temporary exceptions become permanent fixtures. The approval process focuses on granting the exception but never defines success criteria or remediation timelines. What was temporary at approval becomes indefinite in practice.
Risk Acceptance Without Threat Context
Organizations accept risk without understanding the current threat landscape. The decision considers business impact but ignores adversary capability and intent. Risk acceptance becomes a paperwork exercise rather than informed choice.
Audit Closure as Risk Closure
Satisfying audit requirements gets confused with reducing actual risk. Controls are implemented to check compliance boxes while leaving substantive exposures unaddressed. Green audit status masks red risk reality.
Key Pattern: These decisions are individually rational and collectively dangerous. They rarely get documented as risk drivers, making it difficult to learn from them or recognize the pattern before it repeats.
How to Use the Security Decision Registry
For CISOs and CSOs
Security leaders can leverage SDR to shift from reactive control implementation to proactive decision governance. The registry helps you recognize high-risk decision patterns before they accumulate into material exposures.
01
Pattern Recognition
Identify recurring decision structures that historically lead to security failures. Recognize them in real-time before approval.
02
Challenge Narratives
Question "green" status reports that hide structural exposure. Use SDR patterns to probe beneath surface-level assurances.
03
Explain Incidents
Frame incidents in terms of decision history rather than control blame. Build organizational learning from decision analysis.
For Audit & Assurance
Assurance professionals can use SDR to trace findings back to their decision origins rather than stopping at control absence. This approach reveals systemic weaknesses in decision-making processes across domains.
01
Trace Decision Logic
Connect audit findings to the decisions that created them. Document not just what is missing but why it is missing.
02
Identify Systemic Issues
Recognize decision weaknesses that appear across multiple domains. Distinguish one-off failures from patterns.
03
Separate Compliance from Risk
Differentiate formal compliance achievement from actual risk reduction. Assess whether controls address real exposures.
How to Read SDR Documentation
Start by exploring Decision Domains to understand the major categories where security decisions typically occur. Within each domain, review specific Decision Patterns that document recurring scenarios. Focus your analysis on three critical elements: what information was missing when the decision was made, what assumptions were accepted without validation, and what consequences appeared later as the decision aged.
SDR is designed for reflection before approval, not justification after failure.
Decision Domains & Navigation
The Security Decision Registry organizes decision patterns into five core domains. Each domain captures a critical area where security decisions frequently occur and where decision failures have significant downstream consequences.
1
Identity & Access
Decision patterns related to provisioning access, defining privilege levels, managing service accounts, and handling identity lifecycle events. Documents how access decisions made for convenience or speed create long-term exposure.
2
Risk Acceptance & Exceptions
Decision patterns around accepting known risks, granting policy exceptions, and deferring remediation. Examines how temporary becomes permanent and how acceptance without context becomes systemic vulnerability.
3
Audit & Assurance
Decision patterns in responding to audit findings, implementing corrective actions, and defining control sufficiency. Explores the gap between compliance achievement and actual risk reduction.
4
Third-Party & Cloud
Decision patterns for vendor selection, cloud adoption, SaaS integration, and supply chain security. Documents how external dependencies are evaluated and how shared responsibility models are interpreted.
5
Incident & Crisis Management
Decision patterns during incident response, crisis escalation, and post-incident learning. Examines how pressure affects judgment and how lessons get documented versus implemented.
Start Exploring
Each domain contains detailed documentation of decision patterns, including why they occur, how they evolve over time, and how they eventually surface as governance failures, control gaps, or security incidents.
Created by Claudiu Tabac - © 2026
This material is open for educational and research use. Commercial use without explicit permission from the author is not allowed.