Ask SIPB - October 18, 2002

Welcome to Ask SIPB. Due to a formatting error last week, we listed a question about Netscape certificates which we did not answer. We will answer the question this week and talk more about web browsers and certificates.

What is a web certificate?

Web certificates are a digital proof of identity. They are signed by certificate authorities, trusted entities that attest to the certificates' authenticity.

For MIT personal certificates, you identify yourself to the MIT certificate authority using your Kerberos password. Then you are given a signed certificate, proof the MIT authority believes you are who you say you are. Now, any servers that trust the MIT certificate authority will accept your identity. (Example: WebSIS will now let you access your grades.)

As a web surfer, you can also check a web site's certificate and its signatories to decide whether to believe the site is what it claims to be and not an imposter.

If the data sent between your computer and the server will be encrypted, that information should be included on the certificate.

Can I get certificates with Internet Explorer?

Yes, but only on Internet Explorer 5.5 or higher.

In Explorer, visit the MIT Certificate page at Click on "Get MIT CA (Certificate Authority)" to get the master MIT certificate. Click "Open," and then "Install Certificate." Keep clicking "Next" and then "Finish" (accept the defaults). Click "Yes" when prompted to "ADD the following certificate to the Root Store."

Back at the certificate page, click "Get MIT Personal Certificate." Fill out the fields and click "Submit." Click "Next" to accept the default settings, then click "Yes" when asked whether "you want to request a certificate now." Click "Set Security Level" and set to High. Click "Next" and create a password. Click OK to start the certificate acquisition, then click "Yes" to install it.

Why would Netscape claim it is "unable to generate private key"?

Your certificates are probably corrupted in Netscape. To fix this on Athena, close Netscape, go to your prompt, and type:

athena% add infoagents; clear-netscape-password

Now you will need to get new certificates. Go to for more information.

If this problem occurs on Windows or Macintosh, read the detailed instructions at

I was trying to go to WebSIS and got the following error: "Could not initialize the browser's security component. The most likely cause is problems with files in your browser's profile directory. Please check that this directory has no read/write restrictions... "

Your certificates are probably corrupted in Mozilla. Close Mozilla and type at an Athena prompt:

athena% add infoagents; clearcerts

Now you will need to get new certificates. Go to for more information.

What is the new icon where Netscape used to be on Athena (the "ugly red dog")?

The icon is for Mozilla, which is replacing Netscape as Athena's default browser. Mozilla is the product of an Open Source project created by Netscape. It is the basis for Netscape 6 and 7, and includes new features not found in those programs.

The icon itself depicts a "Mozilla," based on Godzilla. "Mozilla" is the original codename for the Netscape browser, a word coined by Netscape founder Marc Andreessen as his "Mosaic killer." Originally colored green, Mozilla became the company mascot in the early days. When Netscape went Open Source the mascot returned in red.

What new features does Mozilla have?

Three new features are tabbed browsing, pop-up blocking, and image blocking.

Tabbed browsing allows you to view many different web pages in one window, reducing desktop clutter. To open a new tab, press Ctrl-T or right-click and choose "Open Link in New Tab." It is easier, however, to enable the option to middle-click to open a new tab: click Edit->Preferences, click the triangle next to Navigator if necessary, click Tabbed Browsing, and check "Middle-click or control-click of links in a Web Page."

Mozilla also offers pop-up blocking, which stops new windows (e.g., ads) from popping up. To activate, go to Edit->Preferences, click the triangle next to Advanced, and click Scripts & Plugins. Then, uncheck "Open unrequested windows." (You can still request windows by clicking on links.) Netscape 7.x, though based on Mozilla, does not have pop-up blocking.

Image blocking allows you to block images (e.g., ads) from certain sites. Simply right-click an image you want to block, and choose "Block Images from this Server." If you ever change your mind, just right-click again and choose "Unblock Images from this Server," or click Tools->Image Manager->Manage Image Permissions, and choose the site to unblock.

Best of all, Mozilla is available on Unix, Windows, MacOS 8/9/X, and many other platforms. You can download Mozilla from

In another column, we'll discuss what other browsers are available for various operating systems.

If you have any other questions, feel free to email us at We'll try to get back to you, and we might put your answer in our next column.