KeepMyWatchIs KeepMyWatch safe?
Short answer
Your alerts are encrypted on your phone with a key that only your phone and your watch have, and opened on the watch. Our relay passes them on without being able to read them. It does see when an alert is sent and how big it is, and so do Apple and Google, who deliver it.
Why the app asks for notification access
To send an alert to your watch, the phone app has to read it, so Android asks you once to grant notification access. You can switch off any app in KeepMyWatch’s Apps list, and turn the access off in Android settings at any time.
The key stays on your two devices
- When you pair, the watch shows a code and the phone scans it. That code carries a random 256-bit key, and it never goes through our servers.
- Each alert is encrypted on the phone with AES-256-GCM using that key, and decrypted on the watch.
- On the phone, the key is itself encrypted with a key held by Android’s Keystore. On the watch, it is kept in the Keychain.
- Requests from the watch, such as a reply or Find my phone, are encrypted the same way and carry a time and a one-time number, so a copied request can’t be replayed.
What our relay sees
| The relay can see | The relay can’t see |
|---|---|
| When an alert is sent, and its size | Who it is from, or what it says |
| A random pairing number and a scrambled form of its access code | The pairing key |
| Push addresses that Apple and Google give your devices | App icons and pictures, which are encrypted too |
An alert your watch hasn’t received yet is kept, still encrypted, for at most one hour. Unlinking the watch and phone deletes everything at once, and a pairing unused for 90 days is deleted automatically. The full list is in the app privacy notice.
Worth knowing
- Apple’s and Google’s push services deliver the messages. They see timing and size, not content.
- The phone app keeps the titles of the last 20 alerts, inside the app on your phone, so you can see what was sent.
- Anyone holding your unlocked phone or watch can read what’s on it, as with any alert.