I wrote this simple swf encryption tool.
It can pack your swf into a packer/shell to prevent your swf being decompiled directly.
SWF Cry is in a very primary status now (v0.02) but it works!
Try it here (my blog post with instructions):
[http://bruce-lab.blogspot.com/2010/08/swf-cry-v002-released-protect-your-swf.html"]http://bruce-lab.blogspot.com/2010/08/swf-cry-v002-released-protect-your-swf.html([URL)]
P.S. Only support as3.
