Privacy policy: BreakingGlass for iPhone

Last updated: 21 October 2026

In short

• BreakingGlass collects no personal data. The app doesn't connect to the internet and uses neither Wi-Fi nor Bluetooth, with one exception: if you print a paper key, iOS sends it over your local network to the printer with AirPrint (section 6). There is no account and no server.
• What you enter in the app is never sent to us or over a network; between iPhones it travels only by QR code. We have no access to it.
• There are no analytics, no tracking, no ads and no built-in crash reporting.

1. Controller

insight 42 UG (haftungsbeschränkt)
Barellistraße 6
85049 Ingolstadt
Germany

Email: support@insight42.com
Phone: +49 841 96 911 766

2. What the app processes, and where

BreakingGlass processes what you enter only on your iPhone:

• The secret you split (a password or text). The app encrypts it on the device and splits the key to it. It is stored only in encrypted form.
• Group data: the group's name, the members' names as you enter them, and how many members it takes to recover the secret.
• Your part: the encrypted package your iPhone receives for each group.
• Device keys: your signing key is created in the iPhone's Secure Enclave and never leaves it. Other keys are kept in the iOS Keychain, set to "this device only".

This data is kept in the iOS Keychain and the app's local database. The app sends it neither to us nor to anyone else. We don't receive it and can't see it.

3. Transfer between iPhones, by QR code only

Data moves between iPhones only through QR codes: one device shows a code and another scans it with its camera, in person and in the same place. Anything secret in a code is encrypted to a one-time key of the receiving iPhone (HPKE, RFC 9180, with X25519, HKDF-SHA256 and AES-256-GCM) and signed by the sender. The one-time key exists only in memory and is discarded afterwards.

The codes also carry public information: public keys, identifiers, digests and signatures, the names members enter for themselves, and, in the invite code, the group's name, the creator's name and how many members it takes. Someone filming the exchanged codes sees at most this kind of information, nothing secret. We take no part in these transfers.

4. Camera

The app uses the camera only to scan QR codes, including the QR code on a paper key. The camera image is processed on the device and neither stored nor sent anywhere. You can revoke access at any time (Settings > BreakingGlass > Camera). The app then can't scan codes; you can still type in a paper key.

5. Face ID

Before your iPhone releases a part or shows a paper key for writing down, iOS asks for Face ID (or Touch ID, or the device passcode). iOS does the check; the app only learns whether it succeeded. Neither the app nor we receive biometric data.

6. Paper keys and printing

Every member gets a paper key. All members' paper keys are created on the creator's iPhone and exist there only in memory; no iPhone stores a paper key. The creator prints them or shows them for writing down before any package leaves their iPhone.

For writing down, the app shows one member's page at a time, only after Face ID, and refuses while the screen is recorded or mirrored, for example by screen recording or AirPlay.

To print, the app uses the iOS print function (AirPrint): iOS sends the document over your local network to the printer you choose. The app itself opens no connection for this. Use a printer you trust; some printers keep print jobs. If you save or share the document from the print function instead of printing it, it goes wherever you send it, for example to the Files app or iCloud Drive. We recommend keeping the paper key on paper only.

7. Backups

If you use iCloud Backup or back up your iPhone to a computer, iOS may include the app's local database. It contains, among other things, the names of groups and members. The keys that open your part are bound to this iPhone and can't be restored on any other device. A backup therefore opens no part, and on a new iPhone your previous part can no longer be used. Apple manages backups according to your settings and Apple's terms; we have no access to them.

8. What we receive

From the app: nothing.

App Store. Apple handles downloads, purchases and updates and is responsible for them; Apple's privacy policy applies. Apple gives us aggregated statistics, such as the number of downloads, which don't relate to you as a person.

Crash reports through Apple, only if you agreed. If you have turned on "Share With App Developers" in iOS (Settings > Privacy & Security > Analytics & Improvements), Apple passes the app's crash reports and usage statistics on to us. They are technical, for example the device model, the iOS version and where an error occurred; we can't link them to a person. We use them only to find and fix bugs. The legal basis is Art. 6(1)(f) GDPR; our legitimate interest is a stable app. You can turn this sharing off in the iOS settings at any time.

If you write to us. If you email us, we process your address and your message to reply. The legal basis is Art. 6(1)(b) GDPR where it concerns a contract, otherwise Art. 6(1)(f) GDPR; our legitimate interest is answering your request. Our email provider, Google (Google Workspace, Google Ireland Limited, Dublin, Ireland), processes messages on our behalf. Data may reach the USA in the process; Google LLC is certified under the EU-U.S. Data Privacy Framework (Art. 45 GDPR), and standard contractual clauses (Art. 46(2)(c) GDPR) apply in addition. We delete the messages once your request is settled, unless a legal retention duty applies. Please never send us a secret, a paper key or a picture of either.

9. No third-party services

The app contains no third-party services for analytics, advertising, crash reporting or sign-in. No data reaches third parties from the app, including in countries outside the EU.

10. Retention and deletion

Your data is kept on your iPhone until you delete it. In the app, "Delete" on a group's page removes that group and your part in it, and "Settings > Erase All Data" removes every group, your parts and your name. If you delete the app, iOS removes its database. Entries in the iOS Keychain may remain on the device afterwards; they are encrypted and usable only by this app on this device. "Erase All Content and Settings" (Settings > General > Transfer or Reset iPhone) removes them completely.

11. Your rights

Under the GDPR you have the right of access (Art. 15), rectification (Art. 16), erasure (Art. 17), restriction of processing (Art. 18) and data portability (Art. 20). You may object to processing based on Art. 6(1)(f) GDPR (Art. 21). To exercise these rights, contact us at the address above. You manage the data in the app on your iPhone yourself; we can neither see nor delete it.

You may also lodge a complaint with a data protection supervisory authority, in particular in the EU member state where you live or work or where the alleged infringement took place (Art. 77 GDPR).

You don't have to give us any data; the app works without it. There is no automated decision-making under Art. 22 GDPR.

12. Changes

If the app changes so that this policy is no longer accurate, we will update it. The current version is at https://breakingglass.insight42.com/privacy/.