Hi,
After reading again and again this topic : Hercules WPE Free - June 14th Patch I saw that people don't really know how to figure out if the keys they are using are broken or not.
So I wrote an online tool to help them (design stolen from jsperf.com).
http://www.robrowser.com/prototype/packet-keys/
This tool simulate 100'000 self encryption of the key to check if it's strong or not (I can set it higher, but it will stress your browser to have the same result).
Bonus, a form to help you generate your own keys.
Have fun~