What is a TLS Certificate? With an example

A TLS certificate verifies a website's security and enables HTTPS encryption between browser and server. Browsers validate certificates by checking validity, trusted issuer (Certificate Authority), expiration, and domain name match. The article examines Google's TLS certificate using CLI commands to decode and display its details. The Google certificate is issued by Google Trust Services, covers numerous subdomains, and employs secure algorithms. Certificates have a validity period, signature algorithm, and include Subject Alternative Names for covered domains. Trustworthiness of a Certificate Authority is determined by its presence in the trusted root store of operating systems and browsers. Certificate Transparency logs and the CA's official website can further confirm the legitimacy of the Certificate Authority. Google Trust Services is deemed trustworthy because it chains to a trusted root certificate and is a recognized CA. Certificate Transparency logs show the CA's activity and widespread use, affirming its reliability. Telegram bots can be used to automate TLS monitoring and provide expiration notifications.