Shift-Left Security & Segregation of Duties: Minimizing NHI Exposure

Securing Non-Human Identities (NHIs) early in the software development lifecycle (SDLC) is essential to mitigating risks associated with API key exposure, insider threats, and credential leaks. A shift-left approach integrates security measures at the design, coding, testing, and deployment phases, reducing unnecessary access to sensitive secrets and ensuring robust Identity Governance and Administration (IGA), Privileged Access Management (PAM), and Segregation of Duties (SoD) policies.

This paper outlines best practices for secure API key management, analyzes architectural frameworks for modern microservices (Kubernetes) and legacy monolithic systems (COBOL, mainframes, serverless), and explores the impact of secret vaults vs. non-secret vault storage solutions. By leveraging Infrastructure as Code (IaC), Configuration as Code (CaC), and automated CI/CD pipelines, organizations can minimize risk exposure and maintain an efficient, scalable, and secure NHI strategy.

Introduction: Securing NHIs in the Software Development Lifecycle (SDLC)

Traditional security measures focus on detecting threats post-deployment, often leaving NHIs vulnerable during development and testing. By shifting security left, organizations can:

• Reduce insider and external risks by minimizing unnecessary access to API keys.
• Eliminate hardcoded credentials in codebases and prevent secrets from leaking in logs.
• Implement proactive security checks in CI/CD pipelines.
• Automate secret rotation and access governance.

Architectural & Secret Management Considerations

Organizations operate across diverse application landscapes, necessitating tailored security models for API key management. This paper categorizes NHI security into four primary use cases:

Each use case presents unique security challenges and best practices, explored in detail below.

Solution Designs for Secure API Key Management

Solution 1: Containerized Microservices with Secret Vault

Use Case:

• Kubernetes (K8s)-based microservices with dedicated secret vaults (e.g., HashiCorp Vault, AWS Secrets Manager).
• IAM roles enforce fine-grained access controls to protect secrets.

Best Practices:

✅ Secrets are injected dynamically into services at runtime via environment variables, preventing hardcoded credentials.
✅Service Accounts & IAM Roles ensure API keys are only accessible to authorized workloads.
✅IaC & CaC enforce security policies at deployment time, reducing human intervention risks.
✅RBAC & Segregation of Duties (SoD) ensure secret access is compartmentalized, preventing unauthorized changes.

Residual Risk Assessment:

✅ Malicious Insider: Needs access to both code & vault (blocked by SoD).
✅External Attacker: Must breach multiple security layers (K8s RBAC, IAM roles, Vault authentication), making exploitation difficult.

Solution 2: Containerized Microservices Without Secret Vault

Use Case:

• Kubernetes applications relying on Kubernetes Secrets or encrypted storage, but without an external secret vault.

Best Practices:

✅ API keys stored in Kubernetes Secrets, encrypted with KMS-backed storage.
✅IAM roles limit access, ensuring only authorized services retrieve secrets.
✅CI/CD pipelines automate secret rotation to prevent stale credentials.

Residual Risk Assessment:

⚠ Higher Insider Threat Risk: Kubernetes admins may access secrets unless strict RBAC policies are in place.
⚠ External Attacker Risk: Misconfigured permissions may expose API keys if not tightly secured.

Solution 3: Monolithic/Legacy Systems with Secret Vault

Use Case:

• Older architectures (e.g., COBOL on mainframes, on-prem applications) integrated with secret vaults for API key storage.

Best Practices:

✅ Secrets are stored in vaults and retrieved dynamically via API calls at runtime.
✅Infrastructure as Code (IaC) provisions access policies, enforcing role-based security.
✅PAM integration protects privileged accounts, reducing unauthorized exposure risks.

Residual Risk Assessment:

⚠ Legacy Systems Have Limited IAM Controls – Additional encryption & monitoring required.
⚠ Operational Overhead of Vault Integration – Older systems may lack native API support, requiring custom implementations.

Solution 4: Monolithic/Legacy Systems Without Secret Vault

Use Case:

• Older applications where secret vaults are not feasible, relying on encrypted files, object storage (AWS S3, Azure Blob), or OS-level security.

Best Practices:

✅ Secrets stored in encrypted files, accessed via secure file permissions.
✅IAM roles control API key retrieval from secure storage.
✅Automation scripts manage key rotation, preventing long-lived secrets.

Residual Risk Assessment:

⚠ Higher Insider & External Attack Risk – OS-level permissions alone are insufficient, requiring additional monitoring.
⚠ Harder to Enforce SoD Policies – Secrets may be exposed to multiple privileged users.

Key Security Enhancements for API Key Protection

1. Decoupling Code from Secrets

• Use environment variables or external vaults to prevent API key exposure in codebases or logs.
• Implement anomaly detection to flag unauthorized access attempts.

2. Enforcing Segregation of Duties (SoD)

• First Line of Defense: IGA & PAM solutions (e.g., Veza, CyberArk) enforce access governance.
• Second Line of Defense: CI/CD pipelines (e.g., OpsMx) require multi-level approvals for secret management changes.

3. Implementing a Double Protection Mechanism

• Dual-layer authentication: API keys are stored in encrypted vaults, requiring both IAM role authentication & KMS decryption.
• Preventing collusion: No single user can access all secrets, reducing the likelihood of insider threats.

4. Automating Secret Rotation & Expiry Policies

• Automated key rotation schedules ensure API keys expire regularly, reducing long-term exposure risks.
• Monitoring & Alerting: SIEM/XDR integration detects unauthorized key access in real-time.

Conclusion: Strengthening API Key Security with Shift-Left & SoD Policies

🔹 A shift-left security approach minimizes API key exposure risks early in development, reducing human error and insider threats.
🔹A multi-layered security model combining IAM, SoD, automation, and anomaly detection ensures API key integrity.
🔹The best security strategy depends on architecture type, with vault-based solutions preferred for modern microservices and legacy mainframe environments.

By adopting the best practices outlined in this paper, organizations can enhance API security, prevent credential misuse, and establish a resilient cybersecurity posture in an evolving digital landscape.

Reference Article: Viresh Garg