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Privacy and Security Preferences - SSL

This section describes how to use the SSL preferences panel. If you are not already viewing the panel, follow these steps:

  1. Open the Edit menu and choose Preferences.
  2. Under the Privacy and Security category, choose SSL. (If no subcategories are visible, click to expand the list.)


SSL Protocol Versions

The Secure Sockets Layer (SSL) protocol defines rules governing mutual authentication between a web site and browser software and the encryption of information that flows between them. The Transport Layer Security (TLS) protocol is an IETF standard based on SSL. TLS 1.0 can be thought of as SSL 3.1.

You should normally leave both SSL checkboxes and the TLS checkbox selected in the SSL Preferences panel to ensure that both older and newer web servers can work with the browser.

Important note re TLS: Some servers that do not implement SSL correctly cannot negotiate the SSL handshake with client software (such as the browser) that supports TLS. Such servers are known as "TLS intolerant."

When the "Enable TLS" option in the SSL preferences panel is selected, the browser attempts to use the TLS protocol when making secure connections with a server. If that connection fails because the server is TLS intolerant, the browser will fall back to using SSL 3.0.

There is currently one important exception to this behavior: If you are using a proxy for SSL connections, the browser will not attempt to use TLS at all. Instead, it will attempt to use SSL 3.0.


SSL Warnings

It's easy to tell when the web site you are viewing is using an encrypted connection. If the connection is encrypted, the lock icon in the lower-right corner of the Navigator window is locked. If the connection is not encrypted, the lock icon is unlocked.

For many people, the lock icon provides sufficient information about a page's encryption status. If you want additional warnings, you can select one or more of the warning checkboxes in the SSL preferences panel. Think carefully about whether you want such warnings, since they can be annoying.

To activate any of these Navigator warnings, select the corresponding checkbox:

  • Entering a site that supports encryption. Select this warning if you want to be reminded whenever you are entering a web site that supports encryption.
  • Entering a site that uses low-grade encryption. Select this warning if you want to be reminded whenever you are entering a web site that supports low-grade encryption. (Low-grade encryption is the weakest encryption available, using 40-bit keys.)
  • Sending form data from an insecure page to an insecure page. Select this warning if you want to be reminded whenever you are submitting data over an unencrypted connection. You may want to select this option even if you don't want any of the others, so you don't inadvertently send sensitive information that isn't encrypted. If you send unencrypted information over the Internet, it can easily be intercepted by other people.
  • Viewing a page with an encrypted/unencrypted mix. Select this warning if you want to be alerted whenever you are viewing a page that includes any information that's not encrypted.

For short definitions, click authentication, encryption, or certificate.

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