> I'm probably naive, but what insights could a government gleam from Push Notifications?
Looking at my own phone right now, it just got a push notification that my wife has arrived at home. That could be useful if you wanted to track my wife.
> And why aren't push notifications E2EE?
That's a great question. And I hope the answer is "we're on it, they will be E2EE in the next release."
If the notifications were to be truly E2EE, it would have to work something like this:
1. Generate a local key pair per app (never uploaded to Apple).
2. Each app can request their public key from iOS (or provided with (void) application:(UIApplication )application
didRegisterForRemoteNotificationsWithDeviceToken:(NSData )deviceToken andPublickKey: (NSData *)publicKey;).
3. App uploads token + public key to their own server.
4. Server encrypts notification payload with the public key before sending to APNS.
5. Apple forwards encrypted payload to device.
6. Device uses the bundle name to look up the local private key and uses it to decrypt the payload.
In this case, no. But as a data point it is useful at providing a named location and a timestamp. Presumably any governmental agency with access to the push notification stream can already determine my wife's home address. We could lie in the app and call some other place "Home" but I expect very few people are resorting to codewords in their mundane daily life.
Looking at my own phone right now, it just got a push notification that my wife has arrived at home. That could be useful if you wanted to track my wife.
> And why aren't push notifications E2EE?
That's a great question. And I hope the answer is "we're on it, they will be E2EE in the next release."