Privacy Policy
Last updated: 16 October 2026
This policy explains what personal data Oruganti Vamsi, trading as Sutranet ("Sutranet", "we", "us") processes when you use Sutranet CAD at cad.sutranet.co.in ("the Service"), why, and what you can do about it. We are responsible for this data (the "Data Fiduciary" under India's Digital Personal Data Protection Act, 2023). Using the Service is also subject to our Terms of Use.
In short: your structural models never leave your browser. We only handle what is needed to run your account and keep usage fair: your sign-in details and hourly counts of your solves, kept for 8 days. We do not sell your data, show ads or use analytics trackers.
1. Your models stay on your device
Models you draw, import or export, and the analysis results, are processed only in your browser. The solver runs on your own device. We do not receive, store or see your models, and we do not keep copies of them. When you run a solve, only a one-way fingerprint of the model is sent (see section 2). Export your work to keep it: it is not saved for you.
2. What we process, and why
| Data | Why | How long |
|---|---|---|
| Account details: your email address, your name (if your Google account provides one) and an account ID, handled by Google Firebase when you sign in. If you sign up with email, your password is stored by Firebase in hashed form; we never see it. | To create your account, let you sign in and identify you to the Service. | Until you ask us to delete your account. |
| Session: a signed session token containing your account ID and email address, held in your browser's memory. | To confirm that requests to the solver come from a signed-in account. | Expires after one hour, or when you close the tab. |
| Solve counts: the number of times your account authorised a solve in each hour. | To apply the usage limit fairly, detect abuse and set fair limits from overall usage. | Deleted automatically 8 days after the hour they count. |
| Model fingerprint: when you run a solve, your browser sends a one-way fingerprint of the structure (a hash of its geometry and member properties). The model cannot be rebuilt from it. | To issue a solve permission that works only for that model. | Not stored. It is placed in the permission sent back to your browser. |
| Solver copy mark: each copy of the solver engine sent to your browser carries your account ID and the time it was sent. | To trace copies used or distributed in breach of the Terms of Use. | Held only in the copy on your device. We do not keep a separate record of it. |
| Suspension record: if we suspend your access to Sutranet CAD under the Terms of Use, your account ID, the date and a short reason. | To enforce the suspension. | Until the suspension is lifted or your account is deleted. |
| Technical request data: IP address, browser type and the pages or files requested, processed by our hosting provider. Short operational logs may include your account ID and the time of a solve. | To deliver the Service, keep it secure and fix problems. | Kept only as long as the hosting provider needs to deliver and protect the Service. |
| Emails you send us, such as bug reports. | To reply and to improve the Service. | As long as needed to deal with your message. |
Without an account. You can open and solve the published verification problems without signing in. We then process only the technical request data above: the session token and the solver copy mark say "guest" and contain nothing about you, and those solves are not counted.
We process this data with your consent, which you give by creating an account or signing in, and because it is needed to provide the Service you asked for. We do not use it for advertising, and we do not sell or rent it.
3. One Sutranet account
Sutranet CAD uses the same account system as other Sutranet products, such as SutranetTower. If you already have a Sutranet account, you can sign in here with it. Deleting your account removes it for all Sutranet products.
4. Who else processes your data
We use these service providers, who process data for us under their own terms and may do so outside India:
- Google Firebase Authentication (Google LLC): sign-in and account storage. The sign-in window is Google's, and Google may use cookies in it under its own privacy policy.
- Cloudflare (Cloudflare, Inc.): hosting, delivery, security and the solve counts.
- Google Fonts: our website pages (not the CAD app itself) load fonts from Google, which receives your IP address when they load.
We may also disclose data where the law requires it, or to protect our rights in a dispute.
5. Cookies and browser storage
We do not set advertising or analytics cookies. To keep you signed in, the Firebase sign-in library stores your sign-in state in your browser's storage. Signing out removes it.
6. Your rights
You can ask us to:
- tell you what personal data we hold about you and how we use it;
- correct or complete it;
- delete your account and its data, which also withdraws your consent (you will then no longer be able to use the Service);
- nominate someone to exercise these rights for you if you die or become unable to.
Email support@sutranet.co.in from the address on your account. We will reply within 30 days. If you are not satisfied with our response, you may complain to the Data Protection Board of India.
7. Security
Data is sent over encrypted connections (HTTPS). Session tokens and solve authorisations are signed and expire quickly. Passwords are handled only by Firebase. No system is perfectly secure, but we take reasonable measures to protect your data. If a breach affects your personal data, we will tell you and the Data Protection Board as the law requires.
8. Age
The Service is for professional use and is not meant for anyone under 18. Please do not create an account if you are under 18.
9. Changes to this policy
If we change this policy, we will update this page and the date at the top. If a change is significant, we will say so when you next sign in.
10. Contact and grievances
For questions, requests or complaints about your personal data, contact Oruganti Vamsi (Sutranet) at support@sutranet.co.in.