[Javascript] Extracting IE encryption level

[Nancy Burton-Vulovic]

Does anybody know how to extract the current encryption level of a user's
browser if they are on IE? Netscape sends:

Mozilla/4.77 [en] (Windows NT 5.0; U)

from which one can extract the U (US, or 128 bit) but IE only sends:

Mozilla/4.0 (compatible; MSIE 5.5; Windows NT 5.0) no matter what the level
of encryption.

Thanks for any info
Nancy