Webmaster Forum / Browsers / Internet Explorer / April 2007

Q: Sometimes when I try to go to a Web site, an alert appears warning me
that the site is not trusted. What the heck does that mean, and is it safe
to visit the site?

A: Web sites used for financial transactions such as shopping or banking use
digital certificates to let your browser know it is dealing with a site that
can be trusted. When you go to access a secure site, the site transmits a
certificate authenticated by a third-party "certificate authority" such as
Go Daddy or Verisign. Web browsers examine the certificates and use coded
keys from the certificate authority and the Web site to establish a secure
connection. Once that is done, any information sent during a transaction is
encrypted so it can't be stolen.

The system isn't perfect. Occasionally, a certificate will expire, or the
secure Web site might use a certificate authority your browser doesn't
recognize, in which case the browser will think something is fishy -- and
you'll get an alert. As a general rule, if you know and trust the site, feel
free to ignore the warning. If not, think twice about doing business on it.

One other note: When you visit a secure Web site, the address for it will
start with https, not http, and a closed lock will appear in your browser
(beside the address bar in Internet Explorer, and at the bottom right of the
screen in Firefox). If you click the lock in Internet Explorer, or point
your mouse at it in Firefox, you'll get confirmation that the site is
secure.

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