FusionCharts can work over HTTPS (Secure Sockets Layer too) in the same way as HTTP.

However, if you're using the dataURL method, you need to set a few headers. Loading XML files in Flash over an SSL Connection in Internet Explorer fails if the Pragma:no-cache or Cache-control:no-cache HTTP headers are set on the XML file or the XML data provider file. The "Cache: no cache" header causes IE to actually return ERROR_INTERNET_UNABLE_TO_CACHE_FILE HTTPS as
the content instead of the XML data.

So, if you're using dataURL method on Internet Explorer, you need to make sure that the server does not send no-cache headers for the XML data. To do so, set the following headers for your XML Data provider page:

Cache-Control: cache, must-revalidate
Pragma: public

When using Firefox or any other browser, you would not find this error. This error occurs only in Internet Explorer.

Also, this happens only in dataURL mode and not in dataXML mode, as in dataURL mode the SWF has to download XML data.