The comment I was replying to stated that each pair would have an AES key generated for them at manufacture, and that is the key they would use to communicate together.
After I posted my reply, the comment was edited to mention this sort of public key exchange you describe happening with a button push. My comment does not apply to this sort of functionality. It would work great, with only the concern you mentioned about a relay attacker. I was only saying having a symmetric key generated at manufacture wouldn't allow for dongle changing and/or dongle consolidation.
After I posted my reply, the comment was edited to mention this sort of public key exchange you describe happening with a button push. My comment does not apply to this sort of functionality. It would work great, with only the concern you mentioned about a relay attacker. I was only saying having a symmetric key generated at manufacture wouldn't allow for dongle changing and/or dongle consolidation.