Cambridge and Arm have made a joint statement that nothing that is essential to the deployment of CHERI ("capability essential IP") is being patented by them: https://www.cl.cam.ac.uk/techreports/UCAM-CL-TR-953.pdf. As with any patent issues, you should consult your legal team and not take anyone else's word for it, because patent law is a minefield and who knows what patents may be out there lurking that nobody realises happens to cover some aspect of CHERI, or design choices in an implementation of it, as with any processor technology, but we are not out to patent it. We believe that the right thing to do is to make the technology open in order to allow it to be widely used for the good of the field.
