Once paired with a bluetooth host, can I block, or appear invisible to other bluetooth hosts?

[sfcris]

Hi, I'm trying to build a bluetooth device that pairs once, and does not have other hosts maliciously or accidentally pair to it (which would create a poor experience for our users).

Once paired with a bluetooth host, can I block, or appear invisible to other bluetooth hosts?

Ideally, I do not want my device to have to advertise again for the original paired host to connect. Ideally the device would be "invisible" except to the original paired host.

If I do have to advertise, I'd like to do such that only the original paired host can attempt to connect.

Only in the initial state, and after a factory reset would the device allow any host to connect.

Is this possible?

And more details, the bluetooth host is expected to be an iPhone or Android device.

Thanks!

[endnode]

Hi, you cannot connect if there is no advertisement, that's how BLE Link Layer works. What "invisible" magic you would like to employ?:) You can implement indirected and directed advertisement so once you don't want to be connectable by other devices you can target only your peer. If you really mean this as security feature then you should anyway check address of connecting device each time you get CONNECT_REQ packet (BLE_GAP_EVT_CONNECTED event if you are using Nordic Soft Device). Protecting your (G)ATT handles by mandating authentication to use them should prevent any damage even if some unknown device would connect but anyway.