4 ms·
Signal Power affects readable distance (signal to noise radius) and the specs for this do suggest the lowest power Bluetooth LTE packets for the shortest "perso
by WorldMaker 2y ago
Signal Power affects readable distance (signal to noise radius) and the specs for this do suggest the lowest power Bluetooth LTE packets for the shortest "personal area network" distance we can get for these FIDO requests.
(It doesn't entirely solve it, you can be extremely unlucky with a radio bounce or a surprisingly quiet Bluetooth radio band at transmission time. Surprising because Bluetooth is somewhat intentionally in one of the noisiest radio bands we've allowed to be extremely noisy.)
- lxgr 2y agoGP mentioned Bluetooth proxying (i.e. using two devices forwarding protocol messages bidirectionally to create a "Bluetooth wormhole"), which doesn't have any obvious inherent distance bound in this protocol, as as far as I can tell.
- 0x457 2y agoI guess it's possible to reduce radius where that attack is executable with signal level.
- lxgr 2y agoUnless there is an API to actively limit the broadcasting signal strength via BLE that authenticator implementations could leverage, I don't see how. And even then you'll quickly run into problems when the attacker's receiver has better antennas in better locations than e.g. the user's laptop.