[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/TLkZOBJj.png



 How can a designer (so I guess who just creates the HDL RTL description) create something in netlist to provide a "Remote IC activation system" that will be used to UNLOCK the device after manufacturing? I mean, how can designer be sure to authorize only legit ones? How is performed?Why cloned cant? 



I mean, the PUF is available/created only after manufacturing, so how can designer know the PUF in advance to authorize that device? How is performed? Why a illegal fab can't create uncloned one and can't be authorized? What is preventing it?