There's a mild yet deep unease that Apple's commitment to privacy could put them in a tough spot as competitors ramp up their data-gathering and machine learning efforts for next-generation digital assistants. Personally, I appreciate Apple's principled stance on privacy as it becomes clearer every day that strong, end-to-end encryption is the only way to keep my data safe from bad actors (including the state).
Recent discussion has concluded that Apple's reluctance to process data in the cloud — you can't turn over what you don't have — means that Siri is never going to get much smarter. After all, Google's assistant will be able to crunch on your search history, location data, and thousands of Gmail messages to deliver the right response. Apple wants Siri to learn too, but only in the local, on-device context. Add an iOS device to your life or replace your phone and it's like Siri is meeting you for the first time.
It seems like an intractable problem: a user profile that never connects through the cloud will be incomplete. How can the devices talk to each other without a potentially compromising holdover on Apple's servers? Simple. The same way they already are: iMessage. Whenever you log into a new device with your iCloud ID, your existing devices go "Hey, hey, hey, I see a new device!" It's because of clever cryptographic infrastructure. Your messages are all signed with a key that isn't unique just to a device, but to a particular set of devices: your devices. If one joins or leaves, that signature changes. Meanwhile, billions of messages are encrypted multiple times and delivered reliably every day. And of course, in the context of iMessage, they can contain attachments, audio or video.
What if little bits of data about your Siri habits could be wrapped up in the same way? Well, Apple has already done that too, going all the way back to the iPod and iTunes' Genius feature. The iPod couldn't compute music recommendations, so it had to be done on the Mac, packaged up, and sent over. If you sync music to an iOS device over USB, you'll still see this happen, with thousands of song similarity files slowly flying by.
So what's to stop creating a similar format for assistant data, encrypt it with the iMessage protocol, and silently sync across devices? If it becomes data-intensive, it could be designed to only trigger when plugged in and on Wi-Fi, like iCloud backup.
I've made this seem like a simple solution, the flick of a switch, when in reality it's the interconnection of several complex pieces of infrastructure. But it's infrastructure that Apple already has built, tested, and proven — they aren't behind. So I'm holding out hope that Siri can keep my secrets and still become more ingenious.