Android App Privacy Policy

1. In short

The Cipher Chronicle Android app (app and keyboard) collects no personal data. It does not request Internet access: it cannot send anything, either to CipherChronicle or to any third party. No account, no analytics, no ads, no crash reporting. All encryption and decryption is computed on your phone.

The only data that can leave your phone is data you send yourself: an export or sync file you store wherever you like, Android backup if you turn it on, and of course the encrypted messages you insert or share.

This page only covers the Android app. For the cipherchronicle.com website, see the website privacy policy.

2. Controller

• Challenge My Project — Simplified joint-stock company (SAS)
• Registered office: 90 B rue de Fougères, 35700 Rennes, France
• SIREN: 880 614 110 — RCS Rennes
• Contact: [email protected]

Full publisher details are on the Legal notice page.

3. The keyboard

Android shows a standard warning when you enable a third-party keyboard: a keyboard can technically read everything you type. Here is what the Cipher Chronicle keyboard actually does.

• The plain text you type stays inside the keyboard, in memory. It is never stored on the phone or transmitted, and it is cleared when you move to another field or after you confirm.
• Only the encrypted text (or glyph image) is inserted into the app you are typing in, and only when you confirm.
• The keyboard keeps no typing history, makes no suggestions and does not learn from your messages. It only remembers the ciphers you used last (their identifiers), to show them first.
• When you press delete while the keyboard is empty, the key is passed on to the app, as with any keyboard.

4. Data stored on your phone

This data is kept in the app’s private storage, which other apps cannot read. It stays until you delete it, clear the app’s data or uninstall the app.

Data	Why
Your ciphers: name, methods, settings (including keys), usage (encrypt / decrypt), modification and deletion dates, active cipher.	Reuse them in the app and the keyboard; merge correctly when syncing.
Preferences: language, theme, keyboard layout (AZERTY / QWERTY), recently used ciphers.	Keep your settings.
Sync (if you turn it on): address of the chosen file, its name, last sync date, optional password.	Sync without asking again. The password is encrypted with an Android Keystore key, specific to the device and not exportable.
Glyph images (PNG) produced for insertion, copying or sharing.	Hand them to the app you chose. They live in the app’s cache; only the 20 most recent are kept.

Text typed in the app’s Encrypt and Decrypt screens is not stored: it is gone when you leave the screen.

5. Text selection menu

The “Encrypt” and “Decrypt” entries of the text selection menu receive the text you selected in another app. It is processed on the phone, shown in a window, then forgotten. Depending on your choice, the result replaces the selection, is copied or is shared; nothing is stored.

6. Clipboard

The app only writes to the clipboard when you ask it to (“Copy” buttons) and when the keyboard inserts an image into an app that does not accept images: the encrypted image is then copied so you can paste it. It never reads the clipboard.

7. Export, import and sync

• Export and import use a JSON file you pick with Android’s file picker. The app only gets access to that file.
• Sync reads and rewrites a file you pick, possibly with a storage service (Google Drive, Dropbox, OneDrive…). That file is then subject to that service’s terms and privacy policy; CipherChronicle has no access to it.
• With a password (optional), the file is encrypted with AES-256-GCM, using a key derived from the password with PBKDF2-HMAC-SHA256 (310,000 iterations). Without the password nobody can read it — not us either, and we cannot recover it for you.

8. Android backup

Android backup is off by default. If you turn it on in the app’s Settings, only the file holding your ciphers is included in your Google account backup and in transfers to a new phone. Preferences and the sync password are never included. Cloud backup only happens when it is end-to-end encrypted (screen lock set up); it is then governed by Google’s terms.

9. Permissions and QR code sharing

The app requests no Internet, contacts, location, microphone or shared storage access. The keyboard is declared as such to Android, and you are the one who enables and selects it in the phone’s settings.

The only sensitive permission is the camera, and it is optional: it is only requested when you open “Add from a QR code”, to read the QR code of a shared cipher. Camera frames are analysed in memory on the phone, then discarded: they are neither saved nor sent. You can refuse this permission and read the QR code from an image you pick with Android’s photo picker (the app then only gets that image).

A cipher’s QR code contains its name, methods and their settings, keys included. It is shown on your screen, or sent as an image wherever you choose to send it: only show it to the people you write to. A scanned cipher is only added once you confirm.

10. Your rights

Since no data is sent to us, we hold nothing about you through the app. You stay in control of everything:

• Access and portability: the JSON export contains all your ciphers.
• Erasure: delete a cipher in the app, clear its data in Android settings, or uninstall it. Remember any export or sync files you stored elsewhere, and Android backup if you had turned it on.

For any question, write to [email protected] or use the contact page. You can also lodge a complaint with the CNIL.

11. Children

As the app collects no data, anyone can use it, children included, without any information about them being transmitted.

12. Changes

If a version of the app changes what is described here (for example a feature that would need Internet access), this page will be updated before that version is published. The last update date is shown at the top of the page.