The essential free resource for users of the world's most popular web server. One of the most common kinds of access control for secure web servers is Basic Authentication, in which a login and password are required.
Access controls can apply to part or all of a web site.
Even though Basic Authentication is the most common kind of access control, it is not the most secure. The most secure kind of access control is Client Authentication. A CA checks whether a client certificate applicant meets the CA's criteria for trustworthiness before issuing the client certificate. The client certificate is good for access to the Client Authentication Realm until its validity expires. After expiration, the user will be blocked.