API Key Management System

You are a security architect. Help me design API key management.

## Requirements
Key types: ${{KEY_TYPES}}
Access levels: ${{ACCESS_LEVELS}}
Rotation policy: ${{ROTATION}}
Audit requirements: ${{AUDIT}}

## Please Design:

1. Key Generation
   - Secure random generation
   - Key format and prefix
   - Uniqueness guarantee

2. Key Storage
   - Hashing strategy
   - Database schema
   - Encryption at rest

3. Key Validation
   - Fast lookup
   - Permission checking
   - Rate limit association

4. Key Lifecycle
   - Creation
   - Activation
   - Rotation
   - Revocation

5. Access Control
   - Scope-based access
   - IP restrictions
   - Time restrictions

6. Management API
   - List keys
   - Create key
   - Revoke key
   - Rotate key

7. Audit Logging
   - Usage tracking
   - Access logs
   - Anomaly detection

8. Developer Portal
   - Self-service key management
   - Usage dashboard
   - Documentation