Is iOS Bluetooth LE encryption mandatory?

Question

My colleagues are developing on a TI CC2540, and they want to sniff the communication as much as possible.

Does the iOS core bluetooth framework support LE Security Mode level 1 (i.e., encryption and authorisation not required) for arbitrary peripherals and services? If it does, the data flow would seem much more transparent.

Answer 1

I would think it would have to, since not all BLE devices use encryption. From Apple's Bluetooth Design Guidelines:

"The Bluetooth accessory should not require special permissions, such as pairing, authentication, or encryption to discover services and characteristics. It may require special permissions only for access to a characteristic value or a descriptor value. See the Bluetooth 4.0 specification, Volume 3, Part G, Section 8.1, fifth paragraph."

Also, from personal experience, no authentication was required to use the key fob included with the TI CC2450 Mini Development Kit. I'm currently using the key fob as a reference platform to add BLE support to techBASIC. I've been able to access all of the key fob features from my own app with no authentication. TI's demo does the same.

So, if any authentication is required to use the CC2540 (and based on the above quote, I don't think it is), it's entirely transparent at the software level.

Just for fun, here's a snapshot of a techBASIC app connecting to the the key fob from TI's CC2450 Mini Development Kit. Again, this was done with no authentication.