I have almost 0 knowledge of IoT, their protocols and usual device constraints. I had a discussion today with someone that has a fair amount of IoT experience and we were discussing some security related issues and the establishment of a shared key came up. I assumed that Diffie-Hellman would be used but this person seemed to not be familiar with the method and based on their knowledge for low power devices, the keys are actually preloaded inside.
- Is this a real scenario?
- Is it possible for DH exchange to be too intensive for a low powered device?
- What role does Ephemeral Diffie–Hellman Over COSE (EDHOC) play in this case? Is it a good alternative or still problematic?