Privacy at Quantenlabor
Stand: 8. September 2026. Diese Hinweise gelten für qubitwerk.com.
In brief
No account, name or email address is required. We do not use advertising or analytics trackers. Please do not enter personal information. Only prepared experiments are offered.
Who is responsible?
Coolblack GmbH, represented by Dirk Nesner, Südfeldwiese 14, 32107 Bad Salzuflen, Germany. Privacy enquiries: info@coolblack.gmbh. Further details are in our Legal notice.
When you visit
Your browser sends technically necessary connection data, particularly your IP address. This website runs on our server at STRATO. Access logging is disabled for Quantenlabor. Fonts and animations are loaded from our own website.
Reading the site does not store a user profile in your browser. Playground programs and your selected language are represented in the URL, so you can share them.
When you request a calculation
Only when you start a calculation do we set the technically necessary cookie __Host-qlab_guest. It contains a random identifier, lasts 24 hours and is transmitted only over encrypted connections. Only a verification value is stored on the server. It associates your jobs and results with your session, including after a reload. It is not a user account.
We store the chosen task, its numeric parameters, job number, timestamps, queue status, result and runtime. A Coolblack-operated computer performs the calculation. It receives the task, but not your IP address or browser identifier. Other guests cannot access your results.
Results become eligible for deletion 24 hours after completion. Automatic cleanup takes place within one further hour. Running and queued jobs remain until completion or expiry. Maximum queue time is six hours. Expired guest identifiers are removed after their jobs have been cleaned up.
Protection against overload
We limit jobs per guest, internet connection and across the lab. For this we use a keyed verification value derived from the IP address; IPv6 addresses are grouped by network. The original IP address is not stored in the job database. Hourly counters expire after an hour, and an accepted job's verification value is deleted with that job. Short-term web-server request limits are kept in memory.
People on the same Wi-Fi share a connection limit. Starting a new guest session does not bypass it. These limits protect operation and do not create advertising profiles.
Storage and recipients
STRATO provides server infrastructure. Processing for this learning lab takes place on our systems in Germany. Guest identifiers, guest jobs and their limit counters are excluded from regular Quantenlabor backups. Temporary guest results therefore cannot be restored after a complete database loss. External sources are opened only when you click their links.
Legal bases and your rights
Technical provision and abuse prevention are based on our legitimate interest in a secure, freely accessible learning service under Article 6(1)(f) GDPR. The necessary cookie serves only the calculation you requested and the association of its results with your session (section 25(2), no. 2 TDDDG).
You can end your guest session on the learning page or delete the cookie in your browser. You then lose access to previous results; their automatic deletion schedule remains unchanged. Without the cookie, you can still view explanations but cannot retrieve session-linked calculations.
Subject to the GDPR, you have rights of access, rectification, erasure, restriction, portability and objection to processing based on legitimate interests. Contact the email address above; do not send access keys. You may complain to a data protection authority, such as the State Commissioner for Data Protection and Freedom of Information of North Rhine-Westphalia. There are no automated decisions producing legal or similarly significant effects.
Legal sources: GDPR and § 25 TDDDG.