Results and Best Practices

In this final part of the experiment, we’ll summarize our findings and provide recommendations for handling Safari ITP in web applications.

Key Findings

1. Third-Party Cookies

ITP effectively blocks third-party cookies by default
First-party cookies are partitioned to prevent cross-site tracking
Cookie access is restricted in cross-site contexts
Cookie expiration is modified to prevent long-term tracking

2. localStorage and sessionStorage

Storage access is restricted in cross-site contexts
Data persistence is limited
Storage operations may fail silently
Partitioned storage is implemented

3. Fingerprinting Prevention

Canvas fingerprinting is modified
WebGL information is restricted
Audio fingerprinting is limited
Font detection is affected

Impact on Web Applications

1. Analytics and Tracking

Third-party analytics may not work as expected
User tracking across sites is limited
Custom tracking solutions need to be ITP-aware

2. Authentication and Sessions

Cross-site authentication may be affected
Session management needs to be adapted
OAuth flows may require modifications

3. User Experience

Some features may break or behave differently
Performance may be affected
User privacy is enhanced

Best Practices

// Instead of
document.cookie = "user=123; domain=.example.com";

// Use
document.cookie = "user=123; SameSite=Strict; Secure";

2. Storage Handling

// Check storage availability
function isStorageAvailable() {
  try {
    const storage = window.localStorage;
    const x = '__storage_test__';
    storage.setItem(x, x);
    storage.removeItem(x);
    return true;
  } catch(e) {
    return false;
  }
}

// Use with fallback
if (isStorageAvailable()) {
  localStorage.setItem('key', 'value');
} else {
  // Fallback to session storage or cookies
}

3. Cross-Site Requests

// Include credentials properly
fetch('https://api.example.com/data', {
  credentials: 'include',
  headers: {
    'Content-Type': 'application/json'
  }
});

4. Fingerprinting Alternatives

// Instead of canvas fingerprinting
// Use server-side session management
const sessionId = generateUniqueId();
storeSession(sessionId, userData);

Recommendations

Privacy-First Approach
- Design applications with privacy in mind
- Minimize data collection
- Be transparent about tracking
Graceful Degradation
- Implement fallbacks for restricted features
- Test with ITP enabled and disabled
- Provide alternative solutions
User Communication
- Inform users about privacy features
- Explain why certain features may be limited
- Provide clear privacy policies
Technical Implementation
- Use SameSite cookie attributes
- Implement proper CORS headers
- Consider using Privacy Sandbox APIs

Conclusion

Safari ITP significantly impacts how web applications handle user tracking and privacy. While it may present challenges for some applications, it ultimately benefits user privacy and security. By following these best practices and recommendations, developers can create applications that work well with ITP while respecting user privacy.