This document confirms that security-related non-functional requirements are met for the Chess Practice App.

• ✅ Status: No external fonts are loaded
• Details: The application uses system fonts only (system-ui, -apple-system, BlinkMacSystemFont, Segoe UI, sans-serif) as defined in src/styles.css
• Source: All fonts are provided by the user's operating system

• ✅ Status: No external icon libraries are loaded
• Details: Chess pieces are represented using Unicode symbols (e.g., ♙, ♜, ♞) defined in src/components/ChessBoard.tsx
• Source: Unicode symbols are rendered directly by the browser

• ✅ Status: No CDN resources are loaded at runtime
• Details: All dependencies are bundled locally via Vite during the build process
• Source: index.html contains no external script or stylesheet links

• ✅ Status: No external APIs are called
• Details: The application operates entirely client-side with no network requests to external services
• Source: Codebase review confirms no fetch(), XMLHttpRequest, or similar API calls

• ✅ Status: No hardcoded secrets or tokens found
• Verification Method: Automated search for common secret patterns (password, secret, token, api[_-]?key, auth[_-]?token) in src/ directory
• Result: No matches found

• ✅ Status: No environment variables are used (not applicable for this client-side application)
• Details: The application does not require server-side configuration or API keys

• ✅ No free-form text input
  • Details: The application only accepts chess moves via drag-and-drop or click/tap interactions
  • Validation: All moves are validated against chess rules before being applied
  • Risk Level: Low - no user-generated content is stored or displayed

• ✅ No user accounts or authentication
  • Details: The application is a single-user, local-only chess practice tool
  • Data Storage: Game state is stored only in browser sessionStorage (cleared when browser session ends)
  • Risk Level: Low - no user data is collected or transmitted

• ✅ No sensitive data storage
  • Details: Only chess move history is stored in browser sessionStorage
  • Data Scope: Move history contains only chess notation (e.g., "e2-e4") with no personal information
  • Persistence: Data is session-scoped and cleared when the browser tab is closed
  • Risk Level: Low - no sensitive information is stored

• ✅ No user-generated content rendering
  • Details: All displayed content is generated from validated chess moves
  • Sanitization: Move notation is generated programmatically and never includes user-provided strings
  • Risk Level: Low - no XSS vectors from user input

• ⚠️ Note: Development dependencies are downloaded from registry.npmjs.org during npm install
• Impact: This is a build-time operation and does not affect runtime security
• Mitigation: Dependencies are locked via package-lock.json to ensure reproducible builds
• Risk Level: Low - only affects development environment

All security-related non-functional requirements are satisfied:

1. ✅ No hardcoded secrets or tokens in client code
2. ✅ No external resources loaded at runtime (fonts, icons, CDN)
3. ✅ No free-form text input
4. ✅ No user accounts or sensitive data storage
5. ✅ All user interactions are validated chess moves only

Last Updated: 2025-01-27 Validated By: Issue #12 - Performance and security validation