Caching authentication and authorization keys in Identity and Access Management (IAM) systems may seem like an effective way to enhance performance, but it poses significant security risks, such as persistent access vulnerabilities and increased attack surfaces. Cached keys can result in stale permissions, instant compromise if accessed by attackers, vulnerability to replay attacks, and race conditions in distributed systems, which can lead to inconsistent access control. Instead of relying on caching, implementing security-first strategies like short-lived tokens, real-time permission verification, centralized authorization, and dynamic permission checks can mitigate these risks. Modern IAM systems and cloud infrastructure can handle the performance demands of real-time verification, making it a safer alternative while maintaining efficient access control. Practical implementations include using token-based authentication with short expiration, refresh mechanisms requiring re-authentication, storing minimal encrypted metadata, and leveraging distributed caching with immediate invalidation capabilities to prioritize real-time security and adapt to evolving threats.