This error typically arises when a system attempting a secure connection cannot verify the authenticity of the other party’s digital certificate. This certificate acts as a digital passport, vouching for the identity of the server. For example, a web browser trying to access a secure website (HTTPS) might encounter this issue if the website’s certificate is expired, issued by an unrecognized authority, or improperly configured. The system’s trust store, which contains a list of recognized certificate authorities, is checked during this validation process.
Secure communication relies heavily on this verification process. Without it, systems are vulnerable to man-in-the-middle attacks, where an attacker intercepts the communication and impersonates the intended recipient. This can lead to data breaches, compromised credentials, and other security risks. The evolution of certificate authorities and trust stores has been instrumental in establishing secure communication over the internet, reflecting an increasing need for robust online security measures.