"Security bolted on after development is a band-aid. Security designed in from day one is the foundation."
What if I told you that 92% of data breaches could be prevented by embedding security into the earliest design phases, not patching it after deployment?
That's the core philosophy behind CuraNexus Analytics, a healthcare and retail data analytics platform I architected from scratch during my Secure by Design (SBD403) subject at Torrens University Australia, under the guidance of Dr. Tanvir Rahman.
This was more than an university project, I approached it as a comprehensive security framework that any organization can adapt when building web-based data retrieval applications.
The Problem Space
Healthcare and retail organizations face a critical challenge: they need to analyze sensitive data across distributed teams while maintaining:
- Confidentiality: Patient health records and payment card data must never leak
- Integrity: Data tampering could lead to misdiagnosis or financial fraud
- Availability: Clinical and business operations can't tolerate downtime
Real-world stakes:
- Healthcare data breaches cost an average of $10.93M per incident (IBM, 2023)
- 45% of breaches involve SQL injection or broken authentication (OWASP Top 10, 2024)
- Insider threats account for 34% of data exfiltration incidents (Verizon DBIR, 2024)
Traditional approach? Build first, secure later. That's backwards.
Assessments Breakdown
Assessment 1: The Foundation (Quiz – Passed ✅)
Before diving into implementation, I needed to master the fundamentals:
- Secure-by-Design principles: CIA Triad, Least Privilege, Defense-in-Depth
- International standards: ISO 27001, NIST SP 800-63B, OWASP ASVS
- Risk frameworks: DREAD scoring, threat modeling, ISMS lifecycle
The insight: Security isn't a checklist—it's a continuous practice.
Assessment 2: Building the ISMS (3000-word Implementation Guide)
The scenario: A 300-employee analytics company with two distinct data domains:
- 100 "Doctors" analyzing hospital records (on-premise, highly sensitive)
- 200 "Retailers" analyzing consumer behavior (cloud-based, commercially sensitive)
My deliverable: A complete Information Security Management System (ISMS) aligned with ISO 27001, including:
1. Risk Assessment (6 Major Threats)
Using the DREAD framework, I quantified risks like:
- Phishing attacks (8.2/10): Mitigated with MFA + quarterly simulations
- Insider data exfiltration (7.0/10): Mitigated with immutable audit logs + SIEM
- Cloud misconfiguration (7.5/10): Mitigated with automated compliance scanning
2. 12-Month Roadmap
Phased implementation across 4 stages:
- Months 1-2: Governance foundation (Security Committee, Risk Register)
- Months 3-5: Technical hardening (MFA, Encryption, Firewall/IDS)
- Months 6-8: Organizational enablement (Training, Phishing sims, BCP)
- Months 9-12: Monitoring optimization (SIEM, Penetration testing)
3. User Training Program
Because humans are the biggest vulnerability:
- Quarterly phishing campaigns targeting <5% click-through rate
- LMS-tracked security awareness modules
- HR-integrated rewards for security certifications
4. Technical Controls
| Control | Standard | Impact |
|---|---|---|
| Multi-Factor Authentication | NIST 800-63B | Reduces credential theft by 99.9% |
| AES-256-GCM Encryption | ISO 27001 §10.1 | Protects data at rest |
| TLS 1.3 | NIST SP 800-52 Rev.2 | Protects data in transit |
| Role-Based Access Control | ISO 27001 §9.2 | Enforces least privilege |
Result: A governance framework that balanced security rigor with operational usability.
Assessment 3: The Security Design Guide (1500-word + 6-min Presentation)
The scenario: Design a replicable security framework for web-based data retrieval applications—not just CuraNexus-specific, but transferable to any organization.
My deliverable: A 4-phase security design guide demonstrated through CuraNexus.
Phase 1: Request (Input Security)
Design Principle: Validate everything before it touches the database.
CuraNexus Implementation:
- Field-level validation: Name (100 chars), Address (150 chars), Phone (15 chars)—all regex-enforced
- SQL injection prevention: 100% parameterized queries, zero raw SQL
- Bot prevention: reCAPTCHA v3 + rate limiting (10 req/IP/min)
- Authentication: MFA via NIST 800-63B, PBKDF2-HMAC-SHA-256 password hashing
- Session security: RSA-signed JWTs, 20-min expiry
Why it matters: 92% of injection attacks happen at the input layer (OWASP).
Phase 2: Retrieve (Database Security)
Design Principle: Encrypt everything, trust no one.
CuraNexus Implementation:
- Data in transit: TLS 1.3 with forward secrecy
- Data at rest: AES-256-GCM with annual key rotation
- Least privilege accounts: Separate credentials for doctors, retailers, admins
- Query protection: ORM-based stored procedures, wildcard escaping
- Integrity checks: SHA-256 digests on every retrieved record
Why it matters: Healthcare breaches cost $10.93M on average—encryption is mandatory (IBM, 2023).
Phase 3: Review (Access Control)
Design Principle: Users see only what they need—nothing more.
CuraNexus Implementation:
-
3-tier RBAC model:
- Normal users: Name, Address, Phone only
- Accounting users: + Credit card data
- Privileged users: All data including medical status
- Technical enforcement: PostgreSQL Row-Level Security
- Audit trail: Immutable logs in WORM storage for 12 months
- Privilege escalation prevention: Separation of Duties (SoD)
Why it matters: Insider threats account for 34% of data breaches (Verizon, 2024).
Phase 4: Risk (Monitoring & Response)
Design Principle: Quantify threats, automate alerts, learn continuously.
CuraNexus Implementation:
-
DREAD scoring for risk prioritization:
- SQL Injection: 8.2/10 → Mitigated via parameterized queries
- Broken Authentication: 7.5/10 → Mitigated via MFA
- Insider Exfiltration: 7.0/10 → Mitigated via SIEM + immutable logs
- SIEM integration: Real-time correlation of security events
- Business Continuity: 4-hour RTO, encrypted S3 backups
- PDCA cycle: Plan → Do → Check → Act (ISO 27001 continuous improvement)
Why it matters: Mean time to detect breaches is 277 days (Ponemon, 2023)—we aim for <1 hour.
Technical Architecture
Backend Stack
| Component | Technology | Purpose |
|---|---|---|
| Web Framework | Python Django | RESTful API + async support |
| Database | PostgreSQL 15 | ACID compliance, Row-Level Security |
| ORM | Django ORM + Django REST Framework | Parameterized queries, migration management, API serialization |
| Authentication | Auth0 / Custom JWT | MFA + SSO support |
| Encryption | AWS KMS | Key management + rotation |
| Monitoring | SIEM (Splunk/ELK) | Real-time threat detection |
Security Stack
| Layer | Control | Standard |
|---|---|---|
| Input Validation | Regex + server-side checks | OWASP ASVS 4.0 |
| Authentication | MFA + PBKDF2 hashing | NIST SP 800-63B |
| Authorization | RBAC + PostgreSQL RLS | ISO 27001 §9.2 |
| Encryption (transit) | TLS 1.3 | NIST SP 800-52 Rev.2 |
| Encryption (rest) | AES-256-GCM | ISO 27001 §10.1 |
| Logging | Immutable WORM + SIEM | NIST SP 800-92 |
What Makes CuraNexus Different?
Traditional approach:
- Build the app
- Run a security audit
- Patch vulnerabilities
- Repeat when breached
CuraNexus approach:
- Design security architecture first
- Implement controls during development
- Monitor continuously via SIEM
- Improve through PDCA cycle
The result:
- Zero SQL injection risk (100% parameterized queries)
- 99.9% credential theft prevention (MFA mandatory)
- <1 hour mean time to detect (SIEM automation)
- Compliance-ready (ISO 27001, NIST, OWASP aligned)
Academic Deliverables
Assessment 2: ISMS Implementation Guide
- 3000 words: Governance, Risk Assessment, 12-month roadmap
- 6 risks quantified via DREAD framework
- 7+ technical controls with standard mapping
- User training program with KPIs
- Grade: TBD (submitted Dec 2025)
Assessment 3: Security Design Guide
- 1500 words: 4-phase framework (Request → Retrieve → Review → Risk)
- 6-minute presentation with A3 poster
- Transferable methodology for any web app
- Grade: TBD (submitted Dec 2025) 🚀
Real-World Applications
This framework is immediately deployable for any data-sensitive web application:
Healthcare
- Electronic Health Records (EHR) systems
- Telemedicine platforms
- Medical billing portals
Finance
- Payment processing gateways
- Banking dashboards
- Loan application systems
Retail
- E-commerce platforms
- Customer analytics tools
- Loyalty program management
Key differentiator: The framework scales from startup MVPs to enterprise systems by adjusting control granularity.
Business Value Proposition
Building CuraNexus taught me that security is a competitive advantage, not just compliance:
Cost Savings
- Average data breach: $10.93M (IBM, 2023)
- CuraNexus prevention cost: <$200K implementation
- ROI: 5000%+ if a single breach is prevented
Regulatory Compliance
- ISO 27001 certification-ready ISMS
- HIPAA/GDPR alignment via encryption + access controls
- PCI-DSS compliant credit card handling
Customer Trust
- Transparent security practices in marketing
- Third-party penetration test results
- Real-time uptime dashboards
Want to Explore the Framework?
While CuraNexus itself is an academic case study, the methodology is fully documented:
- Assessment 2 Report: SBD Implementation Guide
- Assessment 3 Report: Security Design Guide
- Presentation Video: 6-Minute Walkthrough
- GitHub Repository: Masters SWE-AI Projects
Key Takeaways
After 12 weeks of intensive security architecture work, here's what I learned:
1. Security is a Mindset, Not a Tool
You can't buy security—you have to design for it from sprint zero.
2. Standards Are The North Star
ISO 27001, NIST, OWASP aren't bureaucracy—they're battle-tested frameworks that prevent catastrophic mistakes.
3. Humans Are Both the Problem and the Solution
No amount of encryption will save you if your users click phishing links. Training is non-negotiable.
4. Compliance Doesn't Mean Secure
You can check every ISO 27001 box and still get breached. Continuous improvement (PDCA) is the way to go!
5. Security Enables Business
When done right, security accelerates product development by building trust with customers and regulators.
Let's Connect!
Building the CuraNexus Analytics Case Study has been a transformative journey from project manager to security-first software engineer. I'm excited to share the lessons learned and collaborate with others who value secure, scalable software design.
If you're passionate about:
- 🔐 Secure-by-Design architecture
- 🏥 Healthcare/FinTech security
- 📊 Risk quantification frameworks
- 🎓 Academic-to-industry knowledge transfer
I'd love to connect!
- LinkedIn: https://www.linkedin.com/in/lfariabr/
- Portfolio: luisfaria.dev
- GitHub: github.com/lfariabr
References & Further Reading
Academic Papers
- IBM Security. (2023). Cost of a Data Breach Report 2023
- Verizon. (2024). 2024 Data Breach Investigations Report
- OWASP Foundation. (2024). OWASP Top 10 Web Application Security Risks
Standards
- ISO/IEC 27001:2022 – Information Security Management
- NIST SP 800-63B – Digital Identity Guidelines
- NIST SP 800-53 Rev.5 – Security and Privacy Controls
Tools & Frameworks
- DREAD Threat Modeling (Microsoft)
- PDCA Cycle (Deming/ISO)
- CIA Triad (Confidentiality, Integrity, Availability)
Built with ❤️ and paranoia at Torrens University Australia
Subject: SBD403 – Secure by Design
Lecturer: Dr. Tanvir Rahman
Term: T3-2025
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