SDLC (Software Development Lifecycle) security integration is the practice of embedding security activities, tools, and decision points throughout every phase of software development -- from requirements gathering through design, implementation, testing, deployment, and maintenance. Also known as Secure SDLC or DevSecOps, this approach shifts security left into the development process rather than treating it as a final gate before release.
Secure SDLC maps security activities to each development phase. Requirements phase incorporates security requirements alongside functional requirements -- authentication needs, data protection obligations, compliance mandates, and abuse case analysis. Design phase includes threat modeling to identify architectural risks and select appropriate security controls. Implementation phase applies secure coding standards enforced by IDE plugins and pre-commit hooks, with developers trained on common vulnerability patterns. Code review integrates security-focused review alongside functional review. Testing phase layers automated security testing: SAST in CI pipelines, DAST against staging environments, SCA for dependency vulnerabilities, and manual penetration testing for complex attack scenarios. Deployment phase verifies security configurations, runs final compliance checks, and ensures monitoring and incident response capabilities are active. Operations phase maintains vulnerability management, security monitoring, and incident response. Security gates at phase transitions prevent insecure artifacts from progressing -- a critical SAST finding blocks deployment, an unresolved threat model risk blocks design approval. Metrics track defect density, mean time to remediation, and security gate pass rates to measure program effectiveness.
Organizations that bolt security onto the end of development cycles face a painful choice: delay releases for security remediation or accept known risks. Secure SDLC eliminates this dilemma by catching and resolving security issues when they are easiest and cheapest to fix. Teams that integrate security throughout development deliver more secure software faster because security decisions are made alongside engineering decisions rather than after them.
CDA designs Secure SDLC programs through RGA domain operations with VSD providing the technical security activities. Theater missions assess current development processes, identify integration points for security tooling, train development teams, and establish metrics that demonstrate security program maturity over time.