Privacy Policy

Your data,
your control.

OffChain is built on a simple principle: private keys stay on your device. This policy explains exactly what we collect, what we don't, and why.

Last updated: March 2026

01. On Device

Data That Never Leaves Your Phone

All sensitive data is stored exclusively in your device's encrypted secure storage: Android Keystore / iOS Secure Enclave. Nothing is transmitted to our servers unless you explicitly enable SMS mode.

  • Private keys & seed phrase: encrypted on-device, never transmitted in normal mode.
  • PIN hash: a one-way hash stored locally. We cannot recover your PIN.
  • Transaction history & cached balances: stored locally so the app works offline.

02. SMS Mode (Optional)

Data Stored When You Enable Offline Transactions

To send transactions via SMS, you may optionally register your phone number. The following is stored solely to execute your transaction commands:

  • Phone number: used to identify inbound SMS commands.
  • Wallet addresses (public keys): needed to construct transactions.
  • Encrypted private keys: stored server-side solely to sign and broadcast SMS-initiated transactions.
  • Hashed PIN: used to authorise SMS-initiated transactions.
  • Transaction history: amounts, destinations, and on-chain hashes.

You can delete your SMS registration and all server-side data at any time from Settings → Delete Wallet.

03. What We Never Collect

Data We Do Not Touch

  • Name, email address, or government ID
  • Location data (precise or approximate)
  • Device identifiers (IMEI, advertising ID)
  • Your contacts list: names are shown on-device and never uploaded
  • Incoming SMS messages: READ_SMS and RECEIVE_SMS permissions are explicitly blocked

04. Permissions

Why We Request These Permissions

SEND_SMS(Android, optional)

Used exclusively to silently send transaction commands to our relay number when your device has no internet. Never used to contact third parties or read incoming messages.

READ_CONTACTS

Lets you send crypto by name instead of pasting long addresses. Contact data is processed entirely on-device and never uploaded.

USE_BIOMETRIC / Face ID

Handled entirely by your OS. OffChain never accesses, stores, or transmits biometric data.

CAMERA(iOS only)

Used to scan wallet QR codes. Camera access is blocked on Android; QR scanning uses the photo library instead.

05. Security

How We Protect Your Data

  • All app-to-server communication uses HTTPS/TLS.
  • On-device keys use Android Keystore / iOS Secure Enclave.
  • Server-side keys are stored in an encrypted PostgreSQL database.
  • Android backups are disabled (allowBackup: false); key material never appears in Google Drive.

06. Retention, Children & Changes

The Rest

Data Retention

Deleting your wallet via Settings removes all server-side data linked to your phone number. On-device data is removed when you uninstall the app.

Children's Privacy

OffChain is not directed at children under 18. We do not knowingly collect data from minors.

Policy Changes

We may update this policy as the app evolves. Significant changes will be noted in release notes. Continued use constitutes acceptance.