A certificate, also known as a “digital certificate” or a “public key certificate,” is a file that helps keep web communications secure.
Certificates are issued by trusted organizations, such as VeriSign, Inc. or RSA Security, Inc. When you visit an encrypted website—for example, to do online banking—Safari checks if the site’s certificate is legitimate. If it’s not, Safari warns you. Safari supports EV certificates, which require more extensive investigation by certifying agencies.
An encrypted website and Safari work together to encrypt information you exchange with the site. The key used for the encryption is contained in the site’s security certificate. This protects your login information, credit card numbers, addresses, and other secure data.
If you need to connect to a website that requires a personal certificate, you’re provided with a certificate and instructions for installing it. Once it’s installed, you gain authenticated access to the website automatically. If you’re unable to access it, contact the website administrator.