Imprint & privacy

In short

This site sets no cookies and uses no local storage, no tracking and no analytics or advertising services. Nothing is loaded from third parties: fonts, images and scripts come from this server only. The visit counter stores totals only.

Controller

Prof. Dr. Christian Bartelt, address and contact see above, email: christian.bartelt@tu-clausthal.de.

Server log files

To deliver the site, the server processes technically necessary access data on every request: IP address, time, requested address and the browser identifier (user agent). The application itself does not write this data to log files. The host’s upstream web server (reverse proxy) may store it in log files for secure operation, for example to fend off attacks; it is kept only as long as necessary for that purpose and is not combined with other data. Legal basis: Art. 6(1)(f) GDPR (legitimate interest in secure operation).

The visit counter

Once the page has loaded in your browser, it sends one request to this server to count the visit. For this, the server computes a hash (SHA-256) of your IP address, your browser identifier and a random daily value (salt). This way each combination of IP address and browser is counted at most once per calendar day (UTC), and at most 500 visits per day are counted from one IP address. Recognisable bots are not counted, based on the browser identifier.

• The hashes and the daily value exist in memory only, are never written to disk, and are deleted at the day change (midnight UTC) and whenever the server restarts; the daily value is then drawn anew.
• Only the total number of visits, the total number of Otto starts and the counter’s start date are stored. Nothing about you can be derived from them.
• Nothing is stored on or read from your device for this (§ 25 TDDDG).

Legal basis: Art. 6(1)(f) GDPR (legitimate interest in anonymous reach measurement).

Otto starts

When the address ottodidact.org/otto is requested – for example by a language model when an Otto file starts – the server counts one Otto start and redirects to the home page. To avoid double counting it computes the same kind of hash of IP address and browser identifier, kept in memory only, and does not count a second request within 60 seconds. Only the total is stored.

Your rights

Under Art. 15 to 21 GDPR you have the right of access, rectification, erasure, restriction of processing, data portability and objection. To exercise them, contact christian.bartelt@tu-clausthal.de. As the counter stores totals only, it holds no data about you.

You also have the right to lodge a complaint with a data protection supervisory authority, for example Die Landesbeauftragte für den Datenschutz Niedersachsen (the data protection authority of Lower Saxony) (lfd.niedersachsen.de).