Defense in Depth: What It Is & How It Relates to SOC 2 Compliance

In today’s market, clients and partners expect more than promises — they expect proof that their data is safe in your hands. Achieving SOC 2 compliance is one of the best ways to demonstrate that commitment. But to stand out, you need more than a checklist approach. You need a security strategy built to withstand real-world threats.

That’s where the concept of defense in depth comes in. It’s not just about preventing attacks; it’s about creating a resilient system that protects, detects, and responds at every layer of your organization.

As an example, we were tasked with helping a firm with the following security challenges:

• Increasing Cyber Threats: The healthcare industry is a prime target for cybercriminals, who are constantly evolving their tactics. The firm faced a growing number of phishing attempts, ransomware attacks, and insider threats.
• Regulatory Compliance: The firm was subject to strict regulatory requirements, and achieving and maintaining compliance was a priority.
• Client Trust: Clients in the healthcare industry place a high premium on the security of health records and personal identifiable information (PII). Maintaining trust was essential to retaining and attracting clients.

We guided the firm with a defense-in-depth strategy to mitigate these challenges. This layered approach, to successfully get to your information, an outside (or inside) attacker would have to penetrate through your network, your host, your application, and finally your information protection layers.

 

But First…What Is Defense in Depth (DiD)?

Defense in depth is a layered approach to security. Instead of relying on a single barrier, like a firewall or password policy, you implement multiple, overlapping controls. Each layer backs up the others, so even if one fails, the next is ready to respond.

Think of it as your organization’s security ecosystem:

• Outer layers keep attackers out.
• Inner layers monitor and contain threats.
• Core layers protect your most valuable data and assets.

This structure ensures that your security posture remains strong, adaptable, and resilient; exactly what auditors and clients look for in a SOC 2-ready organization.

Building Your Layers: A Practical Framework

A strong defense-in-depth strategy isn’t one-size-fits-all, but most organizations benefit from these five layers:

1. Perimeter Protection: Firewalls, intrusion prevention, and secure network design establish your first line of defense.
2. Endpoint Security: Devices and servers are protected through updates, antivirus, and managed access, ensuring every endpoint is trustworthy.
3. Application & Data Security: Encryption, secure coding, and identity management protect what matters most: your data and your customers’ data.
4. Monitoring & Response: Continuous monitoring, alerting, and defined incident response plans help detect and resolve issues before they escalate.
5. People & Policies: Training, role-based access, and governance processes ensure your team understands and supports your security framework.

Together, these layers form a living, breathing system — one that strengthens over time and adapts to new risks.

 

How Defense in Depth Supports SOC 2 Compliance

SOC 2 focuses on the principles of security, availability, processing integrity, confidentiality, and privacy. A defense-in-depth strategy naturally aligns with each of these.

Here’s how the layered approach supports SOC 2 compliance.

• Security: Multiple controls reduce the likelihood of unauthorized access or data breaches.
• Availability: Monitoring and incident response layers keep your systems reliable and responsive.
• Confidentiality & Privacy: Encryption and access management protect sensitive data end-to-end.
• Integrity: Logging and review processes ensure systems operate as intended and can be verified.

In short, defense in depth helps you move beyond compliance to a position of confidence.

The Business Impact of a Layered Security Model

Adopting defense in depth as part of your SOC 2 readiness delivers measurable business benefits.

• Faster compliance readiness: Multiple layers make it easier to demonstrate control effectiveness during audits.
• Reduced breach exposure: Overlapping protections minimize the chance of a single point of failure.
• Operational resilience: You recover faster and maintain business continuity during incidents.
• Stronger market positioning: Prospects view you as a mature, trustworthy partner — a key differentiator in competitive markets.

Why Prospects Care About This

For potential clients, your SOC 2 report isn’t just a technical document — it’s a reflection of your culture of trust. When you can clearly articulate how you’ve layered your defenses, you signal that your organization:

• Takes security seriously, not just to meet an audit, but to protect customers.
• Understands operational risk and proactively mitigates it.
• Is reliable under pressure with controls that keep working even if one fails.
• Values transparency through documented, verifiable controls.

This builds confidence faster and shortens the trust-building phase in your sales cycle.

 

Defense in Depth & SOC 2 Criteria – What Do Auditors Look For?

The Common Criteria (CC6–CC9) in the SOC 2 framework form the backbone of the Security (Common) category.

• CC6 covers logical and physical access controls. Essentially, how you control who and what can access systems and data.
• CC7 covers system operations, including monitoring, detection, and incident response, or how you manage what happens inside once systems are in use.

The defense in depth model aligns directly with these two sections. Where CC6 is about preventing unauthorized access, CC7 is about detecting and responding when prevention isn’t enough.

Identity & Access (CC6.6)

• Example Controls: SSO, MFA, JIT (just-in-time) access
• Evidence Auditors Accept: IdP configuration exports, MFA policy documentation, quarterly access review reports

Network Security (CC6.6, CC7.2)

• Example Controls: Network segmentation, east-west traffic filtering
• Evidence Auditors Accept: Firewall ruleset differentials, VPC configurations and peering policies, network access control (NAC) reports

Endpoint Protection (CC6.1, CC7.1)

• Example Controls: Endpoint detection and response (EDR), full-disk encryption, application allow-listing
• Evidence Auditors Accept: EDR policy exports, device encryption status reports, endpoint management screenshots

Application Security (CC7.4)

• Example Controls: Static/dynamic application security testing (SAST/DAST), secure SDLC gates, code review requirements
• Evidence Auditors Accept: CI/CD pipeline logs, pull request templates with security checks, SAST scan reports

Data Protection (CC6.1)

• Example Controls: Data loss prevention (DLP), key management service (KMS), automated key rotation
• Evidence Auditors Accept: KMS rotation logs, DLP policy violation reports, backup immutability configurations

Security Monitoring & Response (CC7.2, CC7.3)

• Example Controls: Security information and event management (SIEM), real-time alerting, documented use cases
• Evidence Auditors Accept: SIEM use-case catalog, alert threshold configurations, and incident ticket histories

 

From Defense in Depth to SOC 2 Success

If your goal is to earn SOC 2 compliance while building a program that truly earns client trust, start by assessing your layers.

• Where are your strongest defenses?
• Where do you have single points of failure?
• How are you monitoring and improving over time?

From there, you can develop a roadmap (see the 90-day SOC 2 readiness checklist below) that prioritizes layered controls, measurable outcomes, and alignment with SOC 2 criteria. When done right, defense in depth isn’t just about protecting systems — it’s about building confidence that drives business forward.

90-Day Defense-in-Depth SOC 2 Readiness Checklist

• Days 1–30: Foundations + Access Controls (CC6)

• • Conduct a SOC 2 gap assessment
  • Map controls to CC6/CC7
  • Establish control owners
  • Finalize Access Control, Security, Change Management, and IR policies
  • Implement SSO & MFA organization-wide
  • Implement RBAC and user provisioning/deprovisioning
  • Secure network segmentation
  • Validate firewall and VPN controls

• Days 31–60: Hardening + Detection (CC7)

• • Deploy MDM for all devices
  • Enable full-disk encryption
  • Deploy EDR/antivirus
  • Review encryption for data in transit/at rest
  • Configure centralized logging/SIEM
  • Set up monitoring alerts
  • Implement vulnerability scanning and patch workflow

• Days 61–90: Incident Response + Audit Prep

• • Develop Incident Response Plan
  • Conduct a tabletop IR exercise
  • Implement backup & restore testing
  • Collect SOC 2 evidence (screenshots, logs, policies, scans)
  • Conduct an internal audit readiness review
  • Finalize evidence package
  • Prepare SME teams for SOC 2 audit interviews

Ready to Strengthen Your Defense-in-Depth Strategy?

Defense in depth isn’t built overnight, but with the right roadmap and partner, you can achieve SOC 2 compliance while building lasting security resilience. Whether you’re just starting your compliance journey or refining your existing controls, we’re here to help.

If you are interested in engaging Linford & Company for our auditing services, if you need a SOC audit report, or if you have any questions, please feel free to contact us. Our team consists of IT audit professionals who are highly skilled at SOC 2 audits. We will be happy to answer any questions you may have and to assist with your compliance needs.

This article was originally published on 8/31/2022 and was updated on 11/19/2025.