Last updated: November 10, 2026 · Applies to the Kesher app for Android (package app.chat.messenger) and the web app at chat.wolfschlesinger.com.
Kesher is a private messenger. This policy explains, in plain words, what data Kesher handles, what our server can and cannot see, and how you can delete your data. Kesher is operated by Wolf Schlesinger ("we"). Contact: volvy2577@gmail.com.
1. End-to-end encryption
Your messages, photos, videos, voice messages, files, stickers, reactions, shared lists, announcement cards, edits and call set-up messages are end-to-end encrypted. They are locked on your device before they leave it, with keys that exist only on the devices of the people in the chat. Our server stores and passes on only the encrypted data and cannot read, see or listen to it. Notification previews are decrypted on your own phone.
Voice and video calls connect directly between the phones (peer-to-peer). The call audio and video do not pass through our server, and the set-up messages that start a call are encrypted for the other person's device.
Chat history you import from an export file is parsed and encrypted on your phone; only your own devices can read it.
2. What we collect
Account information
- Email address: used only to sign you in with a one-time code, and for account security (for example a code to reset a chat-lock PIN). It is never shown to other users.
- Phone number (optional, only if you add one): used only for sign-in. Never shown to other users.
- @username, display name, "about" text and profile photo: these are your public profile and are visible to people you chat with and to anyone who looks up your exact @username.
Information needed to deliver messages
- Which chats and groups you are in, group names and group photos, and who is an admin.
- When messages are sent, delivered and read, and the size of messages and files (not their content).
- When you were last active (you can hide "last seen" from others), and a call log (who called whom, voice or video, when, how long).
- Your devices' public encryption keys, your signed-in devices and sessions (including the browser/app name), and the notification tokens of the devices you enabled notifications on.
- Settings that must work across your devices. Most are stored in an encrypted settings file only your devices can open; a few the server needs are stored as plain settings (for example per-chat mute, whether a chat is locked, and disappearing-message timers).
Optional features
- Shabbat & Yom Tov mode and the zmanim bar: if you choose a city or "use my location", the city or an approximate location (city-level) and time zone are saved so Shabbat times can be worked out. We never store an address. You can remove it at any time.
- Encrypted backup: if you turn it on, we store your backup only in encrypted form, locked with your passphrase. We never receive your passphrase, so we cannot open your backup or reset the passphrase for you.
- Translate: if you tap "Translate" on a message and your phone cannot translate it on the device, that one message is sent to our server's translation service, translated, and returned. It is not stored or logged.
- Reports: if you report someone, your app attaches that person's recent messages from your chat to the report (in readable form) so the Kesher team can review it. Only you choose to do this.
- Feedback (bug reports and ideas): the text you write, and if you leave the box ticked, technical details such as the app version, device model/browser, screen size and language. Feedback and reports are not end-to-end encrypted; the Kesher team can read them.
We do not collect your contacts or address book, precise location, advertising ID, or analytics about how you use the app. Kesher has no ads.
3. How we use it
Only to run Kesher: to sign you in, deliver messages and calls, send notifications, keep your devices in sync, prevent spam and abuse (including rate limits based on IP address that are kept briefly), and to answer reports and feedback. We do not sell your data and do not use it for advertising.
4. Who can see your data
- People you chat with see your public profile, and in chats your messages (which only their devices can decrypt).
- The Kesher team (administrators) can see the list of accounts (username, name, email or phone, when created, last active), reports and feedback, and can ban accounts that break the rules. They cannot read your messages.
- Service providers that run Kesher for us: Cloudflare (hosting, database, and on-tap translation), an email delivery service (sign-in codes), Google Firebase Cloud Messaging and web-push services from browser makers (notifications; their content is encrypted), and public STUN servers from Cloudflare and Google that help two phones find each other for a call (they see network addresses, not the call). They process data only on our behalf.
- We may disclose information if required by law. Because messages are end-to-end encrypted, we have no readable message content to hand over.
5. Security
All data is encrypted in transit (HTTPS/TLS). Messages and media are additionally end-to-end encrypted. Profile photos are encrypted at rest on our server. Your private encryption keys stay on your devices.
6. Keeping and deleting data
- Messages you delete "for everyone" and disappearing messages are removed from our server. Expired sign-in codes and old sync events are deleted automatically.
- You can delete your account at any time in the app (Settings → Delete account); it is deleted right away. If you can't open the app, email us and we delete it within 30 days. See Delete your Kesher account.
- If you lose your devices and have no encrypted backup, your old messages cannot be recovered by anyone, including us.
7. Children
Kesher is not directed at children. You must be at least 13 years old (or the minimum age in your country) to use it.
8. Changes
If we change this policy we will update the date above, and for important changes we will tell you in the app.
9. Contact
Questions or requests: volvy2577@gmail.com.