Internet Explorer support for 128-bit encryption, and even 256-bit encryption when running Windows Vista. The problem is most likely the site not recognizing IE7 as being IE5+. You can click here for more information, and make sure you try the User Agent String Utility mentioned there.
Does IE 7.0 not have 128-bit Encryption? If not, how am I able to access this? I tried to download Internet Explorer High Encryption Pack, but when I run it a message pops up saying, "this package cannot install on windows 2000." That's ok, but I use Windows XP Home Ed.