> If you have a unique key embedded in each keyboard/dongle pair, you would lose the ability to do this. In addition, if you lost the dongle, you would be SOL.
I'm not sure I understand why? If public/private key cryptography were used then each dongle & keyboard would contain a private key. The dongle then contains a store for up to X public keys.
The pairing procedure starts due to a physical button press on the two devices, they find each other and exchange public keys. All future communication is then encrypted & signed using the private keys these devices hold. The attack described in venaoy's edit still applies though, an active attacker present during pairing may pretend to be an access point & keyboard, overpowering the original access point and acting as a sort of relay. The link would however break if this relay were to leave the vicinity.
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.
I'm not sure I understand why? If public/private key cryptography were used then each dongle & keyboard would contain a private key. The dongle then contains a store for up to X public keys.
The pairing procedure starts due to a physical button press on the two devices, they find each other and exchange public keys. All future communication is then encrypted & signed using the private keys these devices hold. The attack described in venaoy's edit still applies though, an active attacker present during pairing may pretend to be an access point & keyboard, overpowering the original access point and acting as a sort of relay. The link would however break if this relay were to leave the vicinity.