Certificate authorities for HTTPS, are companies that issue digital certificates confirming that a certain website or domain is genuine and secure. A digital certificate receives information about the owner of the website, as well as the public key used for SSL/TLS encryption. When a website uses HTTPS, the web browser verifies the certificate before the connection is established. During this process, the browser checks whether the certificate was issued by a trusted authority and whether it is still valid. If all factors are in order, the connection to the website is established in encrypted form. Certificate authorities are responsible for monitoring and managing SSL/TLS certificates and thus for the integrity and security of HTTPS connections. There are various certificate authorities, but probably the best known are: Symantec GlobalSign Comodo DigiCert Let's Encrypt