Enable Apple Watch ECG

[tysun]

Hi

ECG is disabled in some countries like Japan. I heard this is done by serial number geofencing. What do you think?

Do you think if I buy an Apple Watch in Japan and then simply pair it with an American iPhone and use an American Apple ID the ECG will be enabled on the Japanese watch?

Is it possible to pen-test an Apple Watch 4/5 for any solutions? If I buy a Japanese watch would you like to try it together?

[jmlluva]

Hi
If the ECG is deactivated in your country, it does not work even if it is paired with an American iPhone.

[tysun]

I understand. Do you think this is deep in the SEP? So not even gaining root can provide a solution such as a config file edit?

[jmlluva]

I wouldn't you know how to tell you for sure. I have an American iWatch and in my country (spain) doesn't activated in was moment. It worked ECG since first day

[pzuccar]

I had a Chilean Apple Watch and a Chilean iPhone and the ECG was not available. I traveled to the USA and bought another Apple Watch. I paired it with my Chilean iPhone while I was still in the States and the ECG worked right away. Today I’m in Chile and the ECG still works, even with watchOS 6.1 beta.

[tysun]

So this proves the serial number is geofenced maybe in the Secure Enclave via a config file created when the watch is activated?

If we SSH is there anything we can check?

[pzuccar]

That would requiere GPS availability during the activation. My best guess is that Apple knows what Apple Watches where sold on an ECG enabled country and they simply enable the functionality based on the serial number or something similar. I think the only way to be sure is to activate an ECG enabled watch in a foreign country.

[tysun]

But how would they enable it? Wouldn't this need to be done at the SEP level?

Or maybe I should ask, how would they disable it?

And why is it not possible for us to gain root and enable it?

If I buy a watch in Japan where ECG is disabled, is there something I can examine through pen-testing?

[pzuccar]

Hello, a little update.

I upgraded to Chilean iPhone 11 Pro Max. Because of the upgrade I had to unpair and reset my US Apple Watch S4. I can confirm that the ECG keeps working once paired again.
Also I bough a new Chilean Apple Watch S5, pair it with the same iPhone, and the ECG does not work.