What is Secure by Design?

Software is Secure by Design if security was considered from the very beginning of the development process and appropriately implemented at every stage of the product development life cycle. This includes recognizing the security risks that are specifically relevant to the software, devising approaches to address those risks, and following security best practices. It is also important to keep the end users of the product secure by considering and addressing their security needs.

Applying the Secure by Design concept to an app establishes a robust security posture, helping to prevent and mitigate cyber vulnerabilities, threats, and risks. This benefits the app's developers, the organization at large, and — importantly — the security of customers and customer data.

Secure by Design can also be applied to existing products through a series of changes, though it is harder to make fundamental architecture or implementation changes. While less ideal, it is still enormously valuable, especially for high-consequence cases. 

Why Secure by Design matters

• Fewer exploitable defects, earlier. Catching issues in design and code review is cheaper and safer than running fire drills after deployment. Adopting Secure by Design cuts rework and reduces incident probability by moving security left and building guardrails into paved paths.
• Customer trust and simpler operations. Products that ship with secure defaults reduce unsafe configurations in the field and lower support burden after release. That’s better for customers and for your brand.
• Clear external alignment. The CISA Secure by Design pledge and related public guidance give leaders a concrete, testable way to demonstrate progress and align roadmaps with what buyers now expect.
• Portable, proven playbooks. Frameworks such as the NIST Secure Software Development Framework (SSDF), OWASP Application Security Verification Standard (ASVS), and OWASP Software Assurance Maturity Model (SAMM) make Secure by Design actionable and measurable across different tech stacks and teams.

Core principles

1. Ensure security is a product requirement, not an afterthought. Treat security defects like any other P0 quality issue, with ownership, service-level agreements (SLAs), and acceptance criteria.
2. Make your products Secure by Default. Ship least-privilege roles, safe toggles, automatic updates, and guardrails that prevent dangerous misconfigurations.
3. Design for abuse and failure. Use a threat model for high-risk features, define trust boundaries, and plan for attacker-controlled inputs and dependency failures.
4. Harden the pipeline. Protect code, builds, and releases — through source integrity, build isolation, artifact signing, provenance, and software bill of materials (SBOM) hygiene — to stop supply chain tampering.
5. Prove it with verification. Use checklists and tests (e.g., the OWASP ASVS) at design review, pull request, and pre-release gates so controls are observable and repeatable.
6. Operate transparently. Provide logs, update channels, and vulnerability handling to help customers stay safe without requiring them to be security experts.

How to implement Secure by Design

The fastest way to operationalize Secure by Design is to give teams paved roads: agreed-upon standards, golden templates, and tools that make the secure way the easy way. The steps below map directly to widely used frameworks so that you can roll out the program without inventing everything from scratch.

1) Set the policy baseline with the NIST SSDF

The NIST SSDF defines a set of secure software development practices that apply across the entire software development life cycle (SDLC), independent of any specific development methodology. Use it to define organization-wide expectations (e.g., threat modeling for new services, code review with security checklists, SBOMs for releases). 

Then, publish a short, concrete Secure by Design policy that includes what must be done (and by whom) before code merges, before a service goes live, and during operations. Keep it concise; link each requirement to SSDF IDs for traceability. 

2) Make security a product and platform goal

Secure by Design is cross-functional. Product leaders set risk tolerances and acceptance criteria, platform engineering teams encode guardrails as defaults, and security teams curate standards and build enablement. Organizational levers (goals, incentives, paved paths) make Secure by Design stick beyond one team or release.

3) Design with threats in mind

Add lightweight threat modeling to your normal design review: Identify assets, trust boundaries, attacker inputs, abuse cases, and must-have controls (authentication/authorization, data handling, logging, update strategy). Document risks and compensating controls where you intentionally defer work. This can be fast (30-60 minutes for most epics), though it may take longer for crown-jewel systems.

4) Build with secure coding and peer review

Codify secure coding standards and make them visible in reviewer checklists. Require peer review for changes to auth flows, crypto, input validation, and permission checks. Backstop reviews with static application security testing (SAST), dynamic application security testing (DAST), and software composition analysis (SCA) built into your continuous integration process; find trends and fix issues at the code owner level rather than scrambling to fix them during the final week. Align your verification to OWASP ASVS levels (e.g., L2 for internet-facing apps). 

5) Protect the supply chain

Harden the build and release system so attackers can’t inject, swap, or tamper with artifacts:

• Isolate build runners; treat them like production
• Sign artifacts and generate provenance; publish SBOMs for major releases
• Adopt SLSA controls as a maturity roadmap — from scripted, repeatable builds to hermetic, verifiable pipelines with attestations

The NIST SSDF gives the “what”; SLSA provides a granular “how” for pipeline integrity. Use both.

6) Ship secure defaults and a safe user experience (UX)

Customers shouldn’t have to choose security. Make the product safe out of the box:

• Enable multi-factor authentication (MFA)/passkey support and secure session management
• Start with least-privilege roles and APIs; provide guided permission grants
• Ensure that logging, updates, and secure transport (TLS) are on by default; block unsafe ciphers and protocols by default
• Provide privacy-respecting telemetry toggles and clear docs for hardening

These practices are explicitly called for in modern Secure by Design guidance and align with the spirit of Secure by Default.

7) Operate, observe, and respond

Plan for life after release:

• Centralize security logging and make it tamper-evident
• Maintain a documented vulnerability intake/disclosure process and patch pipeline
• Continuously verify controls in staging/production (e.g., drift detection for identity and network policies)
• Communicate clearly about fixes and mitigations

These are the customer-facing parts of Secure by Design that build trust and reduce incident impact.

Organizational playbook: Make Secure by Design stick

Set clear acceptance criteria. For example: “Internet-facing apps meet OWASP ASVS Level 2,” “Root cause for critical vulnerabilities includes a design fix,” or “New services require a threat model and owner-approved mitigations.” These standards make reviews objective and repeatable.

Instrument the pipeline. Gate merges on code owner review and security checks; gate releases on policy (e.g., no critical findings, signed artifacts, SBOM produced). Track exceptions with time-boxed approvals. Map each gate to NIST SSDF practices so audits are straightforward. 

Build paved roads. Provide golden templates for services, Terraform modules, authentication libraries, client software development kits (SDKs), and logging. Make the secure way the fastest way via automation and documentation — this is how platform engineering turns “policy” into “muscle memory.”

Align incentives. Recognize teams for Secure by Default improvements, remediation lead time reductions, and adoption of paved paths, not just feature velocity.

Be transparent with customers. Publish security notes, hardening guides, and update policies; offer logs and export capabilities; and respond quickly and clearly to vulnerability reports. This transparency is central to Secure by Design guidance and builds durable trust.

A quick start

1. Adopt the NIST SSDF as your top-level policy and map each requirement to an owner and a gate in your SDLC.
2. Set verification targets with the OWASP ASVS (e.g., Level 2 for public apps). Add the checks to design review and pre-release reviews.
3. Require threat modeling for high-risk epics and every net-new public service; document abuse cases and mitigations.
4. Integrate SAST/DAST/SCA into your continuous integration process, find trends by team, and fix issues before release.
5. Harden the pipeline with isolated builders, artifact signing, provenance, and SLSA-aligned controls. Publish SBOMs.
6. Make secure configs (least-privilege roles, logging, updates on) the default before general availability (GA); document the defaults and the rationale.
7. Operate transparently with customer-visible logs, vulnerability intake, and timely, signed updates.