This set of screen shots shows you what a typical interaction with Netscape when it does not recognize the signer of the certificate.

Note that this process -- adding a new certificate and then subsequently deleting it -- does not work with all browsers and platforms. You can try it in Internet Explorer on a PC, if you like (Click View Certificate when visiting a site with an unrecognized certificate, say https://cs.wellesley.edu > Install Certificate > Next > Next > Finish > Yes > OK > OK > Yes. To remove it, go to Tools > Internet Options > Content > Certificates... > Trusted Root Certificates > cs.wellesley.edu > Remove > Yes > Yes > Close.)

The screen shots below are the result of visiting https://web.mit.media.edu in (an older version of) Netscape on a Mac:

  • Your browser warns you that it doesn't recognize the signer of the certificate:

    browser warning

  • Your browser tells you who signed the certificate and some other facts. In this case, the MIT Media Lab signed their own certificate. (Or is it some spoofer?):

    signer

  • Your browser asks you what to do. Do you (a) accept it for one session, (b) reject it, or (c) accept it forever (until it expires):

    accept or reject certificate?

    For this example, please accept the certificate forever. That will put it in the security info.

  • Your browser warns you about fraud. It gives you the option of being warned all the time:

    fraud warning

  • You get to finish up. If you change your mind, you can delete the certificate.
    finish

    Now, go to the security info and look at your list of certificates. There's the new certificate for the MIT media lab!

    MIT certificate
    If you were doing a demo like this in class, we'd ask you to delete this certificate so that people in the next class can experience this demo. Thanks!