LE Secure Connections (ECDH) on S130

RE: LE Secure Connections (ECDH) on S130

Vahid Shirvani — Fri, 02 Oct 2015 07:21:13 GMT

Any news? Could you update us on the progress? Do you know when we are going to get the LE Secure Connections? This is a crucial feature that is necessary otherwise the encrypted connection could be compromised by the passive eavesdropper.

RE: LE Secure Connections (ECDH) on S130

Ulrich Myhre — Mon, 06 Jul 2015 08:16:13 GMT

Indeed, I was just surprised that mobile vendors basically ignored OOB pairing for so long, but then very quickly accepted a new security mode (and still doesn't support OOB). Not that the community in general want to use it. To me it seemed like the mobile world didn't really care that much about security, but I guess they are just selective in what to include. (nRF52 supports NFC, which is perfect for OOB pairing - among other things).

RE: LE Secure Connections (ECDH) on S130

Dominik — Mon, 06 Jul 2015 08:11:30 GMT

Nice point, reducing the TX power is a good idea. I will keep that in mind for our application! But I don't follow you in your last statement. Since vendors are lacking OOB support, wouldn't that be all the more reason to have LE secure connections which will then spare the necessity for OOB?

RE: LE Secure Connections (ECDH) on S130

Ulrich Myhre — Sat, 04 Jul 2015 15:45:08 GMT

It is also possible to reduce TX power dramatically during bonding, which will require the devices to be very close. This severely limits passive eavesdropping, since a single missed packet of the 6-way "handshake" will make it much harder to regenerate the STK used when distributing the long-term keys.

Sadly, most mobile vendors are still lacking in OOB support, so I'm surprised to see LE-Secure Connections embraced so quickly.

RE: LE Secure Connections (ECDH) on S130

Dominik — Fri, 03 Jul 2015 14:19:59 GMT

Thanks for the clarification! We will see which road to take, either add encryption ourselves or use NFC for OOB pairing. And although a protected environment is a theoretical solution, it is not really practical.

RE: LE Secure Connections (ECDH) on S130

Hung Bui — Fri, 03 Jul 2015 12:43:30 GMT

@Dominik, endnode: Current S130 (v1.0.0) doesn't support LE Secure Connection.

It's in our road map, but I don't know when it will be available.

For official information on future feature/product, please contact our sales representative.

I agree that Just work and Passkey is not very safe, but some measures can be done to make them safer, such as only perform bonding inside a protected environment, such as a Faraday Cage (microwave oven for example)

RE: LE Secure Connections (ECDH) on S130

Dominik — Thu, 02 Jul 2015 14:38:12 GMT

Yes I agree with you, OOB is pretty safe, and I think he also mentions that in his talk. The vulnerability is mainly with JustWorks and the 6-digit Passkey in which case the key exchange is done over the air and unencrypted. I am going to alter my original question.

RE: LE Secure Connections (ECDH) on S130

endnode — Thu, 02 Jul 2015 13:43:11 GMT

Hi Dominik,

I back your question because having this is important for "BLE only" devices to have complete security from the point zero. However I'd like to clarify your claim (supported by the reference to the Blackhat talk) that all 3 security modes (JustWorks, 6-digit Passkey and Out Of Band) are vulnerable to the passive (or even active) attack. My understanding is that in OOB you exchange raw 128-bit AES Long Term Key by other way then over the air and thus you are completely safe. Sure this is applicable only for specific devices/infrastructures (most probably minority) but still it's usable if you want this level of security. Could you point me to any reference for attack against OOB mode?

Thanks for clarification Jan