Enterprise Security Architecture
Security architecture is the discipline of designing systems and organizations to be resilient against attack. Great security architects think like attackers while designing like engineers - building controls that are effective, scalable, and operationally sustainable.
Security Architecture Frameworks
# Major security architecture frameworks
TOGAF (The Open Group Architecture Framework):
Business Architecture → Data Architecture → Application Architecture → Technology
Security integrated at each layer
Used by: Enterprise architects in large organizations
SABSA (Sherwood Applied Business Security Architecture):
Purpose: Align security architecture with business strategy
Layers: Contextual → Conceptual → Logical → Physical → Component → Operational
Each layer answers: What, Why, How, Who, Where, When
Used by: CISOs designing strategic security programs
ISA/IEC 62443 (Industrial / OT Security):
Purpose: Industrial control systems and SCADA security
Security levels SL0-SL4 based on required protection
Used by: Manufacturing, energy, utilities
# Architecture Principles:
Defense in Depth:
Multiple independent security controls - any one failure doesn't cause breach
Example: MFA + EDR + Network segmentation + SIEM + Encryption
Least Privilege:
Every user, service, and system has the minimum access necessary
Admin access is temporary and logged (PAM - Privileged Access Management)
Separation of Duties:
No single person can complete a sensitive action alone
Example: Developer cannot deploy to production AND approve their own change
Fail Secure:
System defaults to secure state on failure
Example: If authentication service fails → deny access, not allow all
Economy of Mechanism:
Simpler designs have fewer attack surfaces and are easier to audit
Complexity is the enemy of securitySecurity Architecture Decision Process
- Threat modeling first - before choosing controls, model the threats. STRIDE (Spoofing, Tampering, Repudiation, Information Disclosure, DoS, Elevation of Privilege) or PASTA (Process for Attack Simulation and Threat Analysis). What are the high-value assets? Who wants them? How would they get them?
- Risk-based control selection - assess risk (likelihood × impact), then select cost-effective controls to reduce risk to acceptable levels. Not every risk requires a technical control - sometimes accepting, transferring (insurance), or avoiding the risk is right
- Security architecture reviews - structured review before new systems deploy: What sensitive data does this system handle? How does it authenticate? How does it communicate? How is it monitored? How is it patched?
- Threat model updates - architecture is not static; threat model must be updated when: new features added, new infrastructure deployed, new threat intelligence emerges
Common Mistakes
- Security review after implementation - changing architecture post-implementation is expensive and incomplete; security reviews must be part of the design process, not a post-delivery gate
- Architecture without operational consideration - a security control that SOC analysts cannot effectively operate (too many alerts, too complex) will be turned off. Operability is a security property
- Inconsistent security standards across teams - a strong security architecture in one team means nothing if another team has unrestricted access or weaker controls that share network access
Tip
Tip
Practice Enterprise Security Architecture in small, isolated examples before integrating into larger projects. Breaking concepts into small experiments builds genuine understanding faster than reading alone.
The foundational security model: Confidentiality (privacy), Integrity (trust), and Availability (uptime).
Practice Task
Note
Practice Task - (1) Write a working example of Enterprise Security Architecture from scratch without looking at notes. (2) Modify it to handle an edge case (empty input, null value, or error state). (3) Share your solution in the Priygop community for feedback.
Quick Quiz
Common Mistake
Warning
A common mistake with Enterprise Security Architecture is skipping edge case testing - empty inputs, null values, and unexpected data types. Always validate boundary conditions to write robust, production-ready cybersecurity code.
Key Takeaways
- Security architecture is the discipline of designing systems and organizations to be resilient against attack.
- Threat modeling first - before choosing controls, model the threats. STRIDE (Spoofing, Tampering, Repudiation, Information Disclosure, DoS, Elevation of Privilege) or PASTA (Process for Attack Simulation and Threat Analysis). What are the high-value assets? Who wants them? How would they get them?
- Risk-based control selection - assess risk (likelihood × impact), then select cost-effective controls to reduce risk to acceptable levels. Not every risk requires a technical control - sometimes accepting, transferring (insurance), or avoiding the risk is right
- Security architecture reviews - structured review before new systems deploy: What sensitive data does this system handle? How does it authenticate? How does it communicate? How is it monitored? How is it patched?