API Key Management
API key management is the process of securely generating, distributing, storing, rotating, and revoking API keys used to authenticate and authorize access to API services.
API keys are simple authentication tokens that identify the calling application or user when making API requests. While less secure than OAuth 2.0 tokens for user authentication, API keys remain widely used for service-to-service communication, usage tracking, and basic access control. Effective API key management is essential to prevent unauthorized access and data breaches.
Secure API key management begins with generation: keys should be cryptographically random, sufficiently long (at least 128 bits of entropy), and unique per client or application. Keys should be transmitted only over encrypted channels and never included in URLs, client-side code, version control repositories, or log files. Server-side storage should use hashing (similar to password storage) so that a database breach does not directly expose usable keys.
Key rotation is a critical practice that limits the impact of compromised keys. Organizations should implement automated rotation schedules, support multiple active keys during transition periods, and provide self-service key regeneration through a developer portal. Each key should have the minimum necessary permissions (least privilege), and usage should be monitored for anomalies such as requests from unusual IP addresses or geographic locations. Expired and compromised keys must be revoked immediately. Organizations should also implement key scoping by restricting keys to specific IP ranges, referrer domains, or API endpoints to limit the blast radius if a key is leaked.