The standard Internet Explorer and Netscape browsers use 40- or 56-bit encryption for secure socket connections - the ones whose URLs begin https:// (note the s at the end). That's weaker than it could be: the optimum legal setting is 128-bit.
To check the encryption depth of your installed version of Internet Explorer, select Help-About. You'll see the current Cipher Strength listed. If it's 40-bit, click the Update Information link for a small download that upgrades the browser to 128-bit encryption. (Unfortunately, there is no encryption upgrade patch, so you will have to install a new full version.)In Netscape Navigator, when you have an online connection, select Help-Software Updates to open a Netscape site; click the Your Installed Software link to find the Cipher Strength. If it's 56-bit, select Upgrade To Netscape Communicator to obtain 128-bit protection.