An “invalid token” generally signifies that a security credential, presented for authentication or authorization, is not recognized or is no longer valid. This often occurs when a system attempts to verify an identifier, such as a session key or API key, and determines that it has been tampered with, expired, or does not match the expected value. For example, a user might receive this message after attempting to use a password reset link that has already been utilized or has passed its expiration date.
The significance of addressing such occurrences lies in maintaining robust security protocols. Properly handling these situations prevents unauthorized access to sensitive data and resources. Historically, managing these identifiers was simpler, but the increasing complexity of modern systems and the proliferation of APIs have made robust token validation mechanisms crucial for safeguarding data integrity and preventing malicious activities like replay attacks and identity theft.
