Dastak Privacy Policy

Effective 17 October 2026. Developer: Abdul Rehman. Contact: support@dastak.app

Dastak is a private app for exactly two people. It is designed so that the content you share — messages, photos, voice notes, files, calls, moods, status lines, questions, answers and locations — is encrypted on your phone before it leaves and can only be read on your partner's phone. The developer cannot read it, and neither can the companies that host the servers. This policy explains what little the service does see, why, and what you can do about it.

Who we are

Dastak is developed and operated by Abdul Rehman, an individual developer. It is offered worldwide. For anything in this policy, write to support@dastak.app.

What is end-to-end encrypted

Everything with content. Each message, photo, GIF, sticker, voice note, file, location, call, mood, status line, photo status, daily question, answer, reaction, edit, profile photo and knock label is encrypted on your device with the Signal Protocol (X3DH, Double Ratchet, post-quantum prekeys) and, for files, AES-256-GCM. The server stores only ciphertext it cannot open and deletes each message the moment your partner's phone confirms receipt. Calls are peer-to-peer and encrypted with DTLS-SRTP; when a direct connection is impossible a relay forwards the encrypted packets without being able to decrypt them.

What the service does see

To work at all, the service needs a small amount of information that is not encrypted:

• Your account: the email address you sign in with and a random account id.
• Your display name, so your partner's phone can show who paired with them.
• The pairing: that two accounts form a couple, and when the pairing was created or ended.
• Knocks: a knock has no content, only a kind (one of three fixed values) and a time. These are stored in plain form and kept until you delete your account.
• Message metadata while a message is in transit: sender, recipient, a type tag (message, call signal, ephemeral), size and time. The ciphertext and this metadata are deleted on delivery.
• Call metadata: that a call started and ended and whether it was audio or video, for the call history and the relay quota. Never audio or video.
• Encrypted files in transit: ciphertext blobs in storage until both sides no longer need them, plus their size and upload time.
• Push tokens: a device token for Google Firebase Cloud Messaging or a UnifiedPush endpoint, so your phone can be woken for a knock, a message or a call. Pushes never contain content — only a type and ids.
• Your public cryptographic keys (identity key, signed prekey, one-time prekeys), which is how end-to-end encryption is set up. Private keys never leave your phone.
• Basic technical logs on the hosting provider (request times, IP addresses, errors) kept for a short period for operation and abuse prevention.

What we never collect

No contacts, no address book, no message content, no media content, no call audio or video, no analytics SDKs, no advertising identifiers, no tracking across apps or websites, no precise location on the server (locations you share travel encrypted inside messages). Dastak shows no ads.

Location sharing

Sharing your location is always something you start on purpose, for a duration you choose, with a persistent notification while it runs, and you can stop it at any time. Coordinates are sent only inside encrypted messages to your partner. The map on the Location screen loads tiles from OpenStreetMap; like any map, that tile request reveals to OpenStreetMap's servers roughly which area is being viewed.

Third parties that process data for us

• Supabase (hosting: database, storage, realtime, serverless functions; region us-east-1, United States) — holds the account and metadata listed above and the ciphertext in transit.
• Google Firebase Cloud Messaging — delivers content-free push notifications on phones with Google services.
• UnifiedPush distributors such as ntfy — the Google-free push option, used only if you install one; the push body is encrypted to your phone.
• Cloudflare — the TURN relay that forwards encrypted call packets when a direct connection fails.
• OpenStreetMap — map tiles on the Location screen.
• Google Play Billing and RevenueCat — process the subscription: Google handles payment; RevenueCat receives your account id, the product bought and its renewal status, and tells our server whether the couple is subscribed. Neither receives content.

These providers act on our instructions and do not receive message content, which they could not read anyway.

Retention

Messages and their metadata: deleted from the server on delivery. Encrypted files: deleted when both sides have them or when a message is deleted for everyone. Knocks, pairing, profile and keys: kept while your account exists. Everything is deleted when you delete your account.

Your choices and rights

• Delete your account at any time inside the app (Settings → Delete account). This removes your account, the pairing, your keys, knocks, push tokens and any ciphertext still in transit. Your partner is notified that the pairing ended.
• Unpair without deleting your account (Settings → Unpair). Both phones discard the shared data.
• Verify there is nobody in the middle: Settings → Safety number, compared in person.
• Request a copy of the account data the server holds, or ask any question, at support@dastak.app. We answer within 30 days.

Depending on where you live you may have further rights (access, correction, erasure, portability, objection). Write to us to exercise them.

Children

Dastak is for adults in a relationship. It is not directed at anyone under 18 and we do not knowingly collect data from children. If you believe a child is using Dastak, contact us and we will delete the account.

Security

Private keys live in your phone's secure storage; the local database is encrypted with a key held in the Android Keystore; screenshots and screen recording are blocked inside the app; notifications never show message text. No system is perfect — report any concern to support@dastak.app.

Changes

If this policy changes materially, the app will show the new version and the date above will change. Continued use after a change means you accept it.