Andreas Pfitzmann
German computer scientist (1958–2010) at TU Dresden who turned anonymity into a research field with its own vocabulary.
In 1991 Pfitzmann, with Birgit Pfitzmann and Michael Waidner, published ISDN-Mixes: a proposal to build David Chaum's mixes into the telephone network so that calls could not be tied to their callers. It was never deployed, but the idea of mixing real-time traffic predated the onion routing behind Tor by several years.
His most-cited work is, somewhat paradoxically, a glossary. From 2000 onward he and Marit Hansen maintained a terminology for anonymity, unlinkability, unobservability and pseudonymity that became the field's shared language. At TU Dresden he also led AN.ON, the anonymisation service later known as JonDonym, and was a frequent voice in German debates on data retention and surveillance.