I am interested in this project and have made a contribution to the Pre-sale.
I was sceptical however about the pretty aggressive marketing of it with a too rich Referral programme.
But I am coming round to the idea that it is a genuine project with great potential.
Here is the patent registration of the KeyCAPTCHA system by Nicholas Prays, the founder of STEX.
https://www.google.com/patents/US20120323700It's important to note that this is just an application. A quick lookup on USPTO will tell you that it was REJECTED and never granted. It failed to pass the requirement of un-obviousness and novelty.