# User Registration Protection

Sign-up forms are a common abuse target: fake accounts used for spam, promo-abuse, account farming for resale, or as a foothold for later credential-stuffing attacks. This page walks through a recommended Sentinel setup for a registration flow.

## What you're defending against

- **Bulk fake sign-ups** — scripted account creation at volume, often from a small number of IP ranges or data-center hosting.
- **Account farming** — accounts created for later resale or abuse, often behaving identically to real users at creation time.
- **Disposable-email abuse** — sign-ups using throwaway addresses to bypass verification.

## Recommended configuration

1. **Enable [Adaptive Captcha](/docs/sentinel/features/adaptive-captcha/)** on the registration form's [Security Group](/docs/sentinel/configure/security-groups/) — sign-up is a good place for slightly higher default friction than, say, a search box.
2. **Keep [Autopilot](/docs/sentinel/features/autopilot/) on** so difficulty adapts if you see a sign-up spike from a bot campaign.
3. **Enable [Threat Intelligence](/docs/sentinel/features/threat-intelligence/)** to catch known-bad IP ranges (data-center hosting, open proxies) commonly used for bulk account creation.
4. **Add a [Rate Limiter](/docs/sentinel/features/rate-limiters/)** on the registration endpoint, scoped per IP and per email domain, to cap how many accounts can be created in a given window.
5. If your form collects free-text fields (bio, company name, etc.), attach them as a [Form](/docs/sentinel/configure/forms/) so the [Classifier](/docs/sentinel/features/classifier/) can flag spammy content at creation time.

## Verifying on your server

Registration still requires the same server-side verification as any other ALTCHA-protected form — see [Server Integration](/docs/integration/server/). Reject the submission if verification fails before creating the account.

## Related

- [Login & Auth Protection](/docs/sentinel/use-cases/login-auth-protection/) — protecting the flow that follows registration.
- [Security Groups](/docs/sentinel/configure/security-groups/)
- [Get Started](/docs/sentinel/get-started/)