Data controller
Cidna is provided by Muhammed Cenna Ramezani Ahdieh (an individual), who is responsible for the data kept on the server. Contact: Use in-app support or email cidna.app@gmail.com.
Data we collect
Phone number (sign-up and sign-in); name, gender and birth date (optional); display-only device info (name, model, OS and app version, masked IP, a one-way installation hash used to recognise reinstalls). Your password itself never reaches our servers: your device derives a separate sign-in value from it, and we store only an Argon2id hash of that value.
Your financial data
Transactions, categories, budgets, debts and savings goals are end-to-end encrypted: the encryption key is generated on your device and leaves it only in wrapped (encrypted) form, and our servers store ciphertext that we cannot read. Your password and recovery key are never sent to us (your device sends only values derived from them that cannot unlock your data), so neither we nor an attacker who compromises our servers can decrypt your financial data without guessing your password. Because of that, please use a long, unique password.
Account details the service needs to operate (phone number, profile fields, device list) are not covered by this encryption. If you lose both your password and recovery key, data cannot be recovered. The on-device database is encrypted too.
SMS & microphone
Where bank-SMS detection exists, SMS text is processed on the device only, and only after you grant the Android permission (you can revoke it any time). The microphone is used only when you choose voice input. Speech recognition is performed by your phone’s speech service; depending on the phone and its settings, audio may be sent to that service’s provider (for example Google). Cidna does not record or store your voice.
Sharing & third parties
We do not sell data or use it for ads. The app contains no third-party advertising, tracking or analytics. Your phone number is passed to our SMS provider to deliver verification codes. PDF/Excel exports and transaction share cards are created only when you ask and go wherever you send them.
Cookies & this website
These pages and the Cidna service use no cookies or tracking tools. This website loads no third-party resources (fonts, analytics, ads) and only remembers your light/dark theme choice in your own browser. The web server may keep standard technical logs (such as IP address and request time) for a limited period for security and troubleshooting.
Retention
Account data is kept while your account is active. Device activity records are kept at most 30 days and temporary sync operations at most 7 days, then erased automatically.
Deleting your account
Delete your account in Settings → Security → Delete Account (see account deletion). Deleted accounts are kept 30 days for restoration, then permanently erased.
Security
HTTPS transport, end-to-end encryption of financial data, password-derived sign-in values hashed with Argon2id, revocable sessions. No system is perfectly secure, and we cannot guarantee absolute security.
Under 18
Use by people under 18 should be with the knowledge and supervision of a parent or legal guardian.
Your rights
You may ask questions, request correction or deletion of your data, and export your financial data as PDF or Excel inside the app.
Changes to this policy
The version and date above are updated on every change; material changes are announced in the app.
Contact
Use in-app support or email cidna.app@gmail.com.