How to encrypt my own IP block

[Altera_Forum]

I have tried to look for this info but unsuccessfully so far.. I wonder if someone can help: 

 I want to create an IP block to a client that will be instantiated via sopc builder but I wouldn't want them the access to the source code. Is it possible to encrypt the contents in a similar manner as most all Altera IP is ?  Even obfuscating would help but I'm not sure how to best go about that.

[Altera_Forum]

try .qxp with a clear text instantiation wrapper which becomes the top level of the custom component for synthesis, and simgen to create a simulation netlist (.vo/.vho). you'll lose parameterization, but it should work otherwise (i haven't fully tested it, the method may need some tweaking): 

 using .qxp: http://www.altera.com/support/kdb/solutions/rd06242008_7.html  using simgen: http://www.altera.com/support/kdb/solutions/rd07132006_347.html   alternatively, you may try requesting the encryption tools from Altera through an SR