Secure Software Development

Secure Software Development is a software engineering discipline focused on integrating security practices throughout the entire software development lifecycle (SDLC). Rather than treating security as an afterthought or a feature to be added later, this proactive approach aims to build software that is inherently resilient to malicious attacks from its conception. It involves systematically applying principles and techniques—such as threat modeling during design, writing secure code, and performing rigorous security testing—to identify and mitigate vulnerabilities early, thereby minimizing the attack surface and protecting data and system integrity from the outset.

1. Introduction to Secure Software Development
   1. Core Concepts
      1. Defining Secure Software
         1. Characteristics of Secure Software
         2. Security vs. Safety
         3. Security as a Non-Functional Requirement
      2. Security as a Quality Attribute
         1. Security in the Software Quality Model
         2. Balancing Security with Performance
         3. Balancing Security with Usability
         4. Balancing Security with Maintainability
      3. The Cost of Insecurity
         1. Financial Impact of Security Breaches
         2. Reputational Damage
         3. Legal and Regulatory Consequences
         4. Operational Disruption Costs
      4. Shifting Security Left
         1. Early Integration of Security in Development
         2. Benefits of Early Security Considerations
         3. Barriers to Shifting Left
         4. Cultural and Organizational Changes
   2. Fundamental Security Principles
      1. CIA Triad
         1. Confidentiality
            1. Data Protection
            2. Access Control
            3. Information Disclosure Prevention
         2. Integrity
            1. Data Integrity
            2. System Integrity
            3. Non-Repudiation
         3. Availability
            1. System Uptime
            2. Denial of Service Prevention
            3. Disaster Recovery
      2. Defense in Depth
         1. Layered Security Controls
         2. Redundancy and Diversity of Defenses
         3. Multiple Security Boundaries
      3. Principle of Least Privilege
         1. Limiting User Permissions
         2. Limiting Process Permissions
         3. Privilege Escalation Risks
         4. Just-in-Time Access
      4. Fail-Secure Design
         1. Secure Failure Modes
         2. Handling Exceptions Securely
         3. Default Deny Policies
      5. Separation of Duties
         1. Dividing Responsibilities
         2. Preventing Fraud and Abuse
         3. Multi-Person Authorization
      6. Attack Surface Minimization
         1. Reducing Exposed Interfaces
         2. Disabling Unused Features
         3. Minimizing Code Complexity
      7. Secure Defaults
         1. Default Configurations
         2. Secure Out-of-the-Box Settings
         3. Configuration Hardening
      8. Economy of Mechanism
         1. Simplicity in Design
         2. Reducing Complexity to Minimize Errors
         3. Clear and Simple Interfaces
      9. Open Design
         1. Security by Design vs. Security by Obscurity
         2. Public Review of Security Mechanisms
         3. Transparency in Security Architecture
      10. Psychological Acceptability
          1. Usable Security Features
          2. Avoiding User Workarounds
          3. Security Awareness Training
   3. The Secure Software Development Lifecycle
      1. Integrating Security into the SDLC
         1. Security Activities in Each Phase
         2. Security Champions and Roles
         3. Security Training for Development Teams
      2. SDLC Models and Security Integration
         1. Waterfall Model
            1. Security in Sequential Phases
            2. Limitations for Security Integration
            3. Security Gates and Reviews
         2. Agile and DevSecOps
            1. Security in Iterative Development
            2. Continuous Security Practices
            3. Sprint Security Activities
         3. Spiral Model
            1. Risk-Driven Security Activities
            2. Iterative Risk Assessment
            3. Security Prototyping
      3. SSDLC Frameworks and Models
         1. Microsoft SDL
            1. SDL Phases
            2. Core Practices
            3. Implementation Guidelines
         2. OWASP SAMM
            1. Maturity Levels
            2. Assessment Framework
            3. Improvement Roadmaps
         3. BSIMM
            1. Measurement and Benchmarking
            2. Core Practices
            3. Industry Comparisons
         4. NIST Secure Software Development Framework
            1. Practices and Tasks
            2. Implementation Guidance