This section describes how to use the SSL preferences panel. If you are not
already viewing the panel, follow these steps:
Open the &brandShortName;Edit menu and choose Preferences.
Under the Privacy & Security category, click SSL. (If no
subcategories are visible, double-click Privacy & Security 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 these three checkboxes selected to ensure that
both older and newer web servers can work with the browser:
Enable SSL version 2: Allows older web servers to work
with the browser.
Enable SSL version 3: Allows newer web servers to work
with the browser.
Enable TLS: Allows web servers that support TLS to take
advantage of it.
To turn individual ciphers on or off, click the Edit Ciphers button:
Edit Ciphers: Don't attempt to edit ciphers individually
unless you know exactly what you are doing and have cleared the changes
with your system administrator. For more information, see
Edit Ciphers.
Important note regarding 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.
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.
If you want additional warnings, you can select one or more of the warning
checkboxes in the SSL preferences panel. Some people find these warnings
annoying.
To activate any of these Navigator warnings, select the corresponding
checkbox:
Loading a page that supports encryption: Select this
warning if you want to be reminded whenever you are loading a page that
supports encryption.
Loading a page that uses low-grade encryption: Select
this warning if you want to be reminded whenever you are loading a page
that supports low-grade encryption. (Low-grade encryption is the weakest
encryption available, using 40-bit keys.)
Leaving a page that supports encryption: Select this
warning if you want to be reminded whenever you are leaving a page that
supports encryption for one that does not.
Sending form data from an unencrypted page to an unencrypted
page: Select this warning if you want to be reminded whenever you
are submitting data over an unencrypted connection. 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.
This section describes how to use the Edit Ciphers dialog box. If you're not
already viewing it, follow these steps:
Open the &brandShortName;Edit menu and choose Preferences.
Under the Privacy & Security category, click SSL. (If no
subcategories are visible, double-click Privacy & Security to expand
the list.)
Click the Edit Ciphers button.
The Edit Ciphers dialog box allows you to select or deselect ciphers, or
cryptographic
algorithms. Consult your system administrator before changing any of
these settings.
Each checkbox corresponds to a cipher suite, or set of cryptographic
algorithms. To view information about a cipher suite, click the
Details button besides its name.
The following information is displayed for the selected cipher suite:
Cypher: Encryption module name.
Encryption algorithm: Used for bulk encryption and
decryption.
Authentication Algorithm: Used to determine the server
or client's identity.
Effective Key Algorithm: Governs the way in which the
server and client determine the symmetric keys they will both use during an
SSL session.
Key Size: The size of the keys used with this cipher
suite. (Encryption strength depends on both encryption algorithm and key
size.)
MAC Algorithm: Used for tamper detection and data
verification; sometimes called message digest or hash algorithm.
Other Attributes: These can include the following:
FIPS Complies with Federal Information Processing
Standards Publications (FIPS PUBS) 140-1. Many products sold to the US
government must comply with one or more FIPS standards.
IsExportable Cipher suite was legally exportable
under regulations published by the U.S. Department of Commerce that
previously limited the encryption strength of exported products. Those
regulations have since been loosened.
For more information about ciphers and encryption, see the following online
documents: