Privacy-by-Design Video API Patterns

The Seven Privacy Principles Applied to APIs

Privacy-by-design originated with Ann Cavoukian's seven foundational principles. Here's how they apply to video API design:

1. Proactive not reactive: Don't wait for breaches — prevent them architecturally
2. Privacy as default: Maximum privacy with zero configuration
3. Privacy embedded in design: Not a feature, an architecture
4. Full functionality: Privacy AND utility, not privacy OR utility
5. End-to-end security: From upload to deletion
6. Visibility and transparency: Users know exactly what happens
7. Respect for user privacy: User interests come first

Minimal Collection Patterns

Accept Only What You Need

Don't require metadata you won't use:

# Good - minimal required fields
POST /v1/enhance
{
  "video_url": "https://...",
  "output_format": "mp4"
}

# Bad - collecting unnecessary data
POST /v1/enhance
{
  "video_url": "https://...",
  "user_name": "...",      // Why?
  "user_email": "...",     // Why?
  "device_info": "...",    // Why?
}

Anonymous Processing

Allow processing without identifying the user:

• API key identifies the account, not the end user
• No user metadata required in requests
• Correlation IDs are ephemeral, not persistent identifiers

No Telemetry on Content

Analytics should track usage patterns, not video content:

• ✓ Track: request count, processing time, error rates
• ✗ Don't track: video content, faces detected, objects in frame

Purpose Limitation Patterns

Single-Purpose Endpoints

Each endpoint does one thing:

• /v1/enhance — enhances video, nothing else
• /v1/transcode — transcodes, doesn't analyze
• No "also analyze while you're at it"

No Secondary Use

Processed video is never:

• Used for training
• Aggregated for analytics
• Shared with third parties
• Retained beyond delivery

Explicit Processing Scope

The API response shows exactly what was done:

{
  "job_id": "job_abc123",
  "processing": {
    "operations": ["upscale_2x", "sharpen", "denoise"],
    "model_version": "real-esrgan-x2plus-v1.4",
    "no_face_restoration": true
  }
}

Storage Limitation Patterns

Automatic Expiration

All stored data has a built-in expiration:

• Output URLs: 24 hours default
• Job metadata: 30 days
• Audit logs: 90 days

On-Demand Deletion

Users can delete immediately:

DELETE /v1/jobs/{job_id}

Response:
{
  "deleted": true,
  "deleted_at": "2026-07-11T14:30:00Z",
  "certificate_url": "https://..."  // Secure tier
}

No Retention Upgrade Path

There's no way to "keep it longer" after the fact. Retention must be specified at upload time.

Security by Default Patterns

Encryption Required

• HTTPS-only — no HTTP endpoints
• TLS 1.3 minimum
• Certificate pinning for SDKs

Authentication Always

• No anonymous endpoints
• API key required on every request
• Key rotation support

Rate Limiting and Abuse Prevention

• Per-key rate limits
• Abuse detection (unusual patterns)
• Automatic throttling

Fail Secure

When something goes wrong, fail toward privacy:

• Processing error → delete input and output
• Network timeout → container destroyed
• Authentication failure → no access, full stop