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Privacy Policy

Last updated: 2026-03-04

1. Who We Are

Michal Repasek Software ("we", "us", "our") operates the Sudoku Corner web application. Our registered address is: Dlouha 162, 25063 Mratin, Czech Republic.

2. What Data We Collect

We collect the minimum data necessary to provide the service:

Account dataNickname, email address, hashed password
Game dataMatch results, scores, ELO ratings, solve times
Technical dataIP address, browser type (for security and abuse prevention)
CookiesEssential cookies only (session, security, login) — see below

We do not collect payment information, location data, or data from third-party social logins.

3. How We Use Your Data

Your data is used to operate the game: authenticate your account, match you with opponents, calculate ratings, display leaderboards, and send notifications you've opted into. Technical data is used to prevent abuse (rate limiting, ban enforcement).

For usage statistics we run a self-hosted analytics tool (Umami) on our own infrastructure. It is cookieless, collects only anonymized, aggregated data (page views, referrers, device type), and no data ever leaves our servers or is shared with any third party.

4. Legal Basis (GDPR)

For users in the European Economic Area, our legal bases are:

ContractProcessing necessary to provide the service you signed up for
Legitimate interestSecurity, abuse prevention, service improvement

5. Cookies

We use only essential (technical) cookies:

Essential cookies Session management, CSRF protection, login persistence ("remember me"). These are required for the application to function.

We do not use any advertising, tracking, or third-party cookies. Our analytics (self-hosted Umami) works entirely without cookies. Because only strictly necessary cookies are used, no cookie consent banner is required.

6. Data Sharing

We do not sell or share your personal data with third parties for marketing purposes. Data may be shared with:

AnalyticsSelf-hosted (Umami) on our own servers — no third party involved
Hosting providerServer infrastructure (data processing agreement in place)
Law enforcementOnly if required by applicable law

7. Data Retention

Account data is retained as long as your account is active. If you delete your account, personal data is removed within 30 days. Anonymized game statistics may be retained indefinitely. Server logs are retained for up to 90 days.

8. Your Rights

Depending on your jurisdiction (GDPR, CCPA), you have the right to:

AccessRequest a copy of your personal data
RectificationCorrect inaccurate data via Settings
DeletionRequest deletion of your account and data
PortabilityReceive your data in a structured format
Withdraw consentRevoke analytics cookie consent above

To exercise these rights, contact the service operator.

9. Children

Sudoku Corner is not directed at children under 13. We do not knowingly collect data from children under 13. If you believe a child has provided us with personal data, please contact us.

10. Changes to This Policy

We may update this policy from time to time. Material changes will be communicated via a notification on the platform. Continued use after changes constitutes acceptance.

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