Having a secure website is essential if you are using HTTP to connect to, say, a corporate database. Windows NT and 2000 websites can be secured using the following:
Clear Text Authentication. The username and password are sent down as an HTTP header, visible to others unless secure sockets are used.
NTLM (NT LAN Manager) Authentication. A challenge-response scheme that bases the challenge on the username.
If an HTTP request fails authentication, an error 401 will be returned if the error originates in a web server, or 407 for a proxy server authentication failure. These errors are returned in HTTP headers from the server. If your application receives a 401 or 407 error, a valid username and password should be supplied. ...