Goodcoin – Robust Privacy for Loyalty Programmes and Payment Systems

Goodcoin is a three-year research project – throughout this time a data protection-friendly bonus point and customer loyalty system will be developed. The lead partner of the project is the Humboldt University of Berlin; accompanying research is carried out in cooperation with the Humboldt Institute for Internet and Society as well as with Bonsum UG.


Reconciling conflicting interests through technological innovation


Bonus and loyalty point systems are often used to analyse the purchasing behavior and to create comprehensive profiles of customer interests. This data helps retailers to provide personalized offers and to approach potential customers. In order to reconcile the customers interests of informational self-determination with the objectives of retailers, this research project aims at a data protection-friendly design of the Goodcoin system.

Customers will remain anonymous during digital shopping, which prevents the creation of consumer profiles by online retailers. Nevertheless, the system is able to statistically evaluate the consumption behavior in order to determine new market trends and to align retailers’ supply structures at an early stage. The project also explores possibilities for implementing data protection-friendly product recommendation systems. If requested, customers can also receive digital advice on products. The concepts in development are based on innovative encryption and anonymisation procedures. When paying online, customers should be able to use anonymous, digital value units: the GoodCoins. The GoodCoins serve as digital coins and represent bonus points for purchases made at the same time.

The private-sphere-friendly realisation of an everyday bonus and customer loyalty system makes a decisive contribution to the technically supported reconciliation of competing rationalities. Innovation serves as a means of resolving governance conflicts.

Duration01/2016 – 12/2018
SponsorsThe project Goodcoin is part of the BMBF-network project “Datenschutz: selbstbestimmt in der digitalen Welt”


Julian Hölzel

Associate Researcher: Data, actors, infrastructures

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Former employees

Journal articles and conference proceedings

Hölzel, J. (2018). Anonymisierungstechniken und das Datenschutzrecht. Datenschutz und Datensicherheit, 42(8), 502–509. Publication details

Other publications

Hölzel, J. (2017). Bitcoin – Plutokratie auf Raten? Digital Society Blog. Publication details

Lectures and presentations

PETable GDPR? Anonymization Techniques and the Law
PET-CON 2018.1: 8th Privacy Enhancing Techniques Convention. GI: Fachgruppe Datenschutzfördernde Technik. Einstein Center Digital Future, Berlin, Germany: 20.05.2018

Julian Hölzel

Personenbezug hat als Unterscheidungskriterium ausgedient: Wie Grundrechte und Grundfreiheiten auch durch die Verarbeitung nicht-personenbezogener Daten bedroht werden können
Digitalisierung und Mobilität: Grundsatzfragen Informationsfreiheit und Datenschutz. instkomm – Institut für Kommunikationsforschung. Europäische Akademie, Berlin, Germany: 17.07.2017

Jörg Pohle, Julian Hölzel

Richterratschlag 2016: Kryptografische Währungen am Beispiel von Bitcoin. Justizakademie Nordrhein-Westfalen, Recklinghausen, Germany: 05.11.2016

Neue Richtervereinigung - Zusammenschluss von Richterinnen und Richtern, Staatsanwältinnen und Staatsanwälten e.V.

Organisation of events

Privacy: Historischer Überblick und Vergleich ausgewählter Konzepte
Security und Privacy in dezentralen Systemen. From 01.11.2017 to 14.02.2018. Humboldt-Universität zu Berlin, Berlin, Germany. Co-Organised by: Schoppmann, Phillipp; Sparka, Hagen; Brack, Samuel; Henningsen, Sebastian; Scheuermann, Björn; Dietzel, Stefan (National)

Julian Hölzel

Geschichte und Theorie des eGovernment
with attending Vip: Klaus Lenk. 19.04.2017. Alexander von Humboldt Institut für Internet und Gesellschaft, Berlin, Germany (National)

Julian Hölzel, Jörg Pohle

Regulatorische Aspekte von Kryptowährungen
Digitale Währungen (M.A. Informatik/Humboldt-Universität zu Berlin). with attending Vip: Samuel Brack. From 18.04.2017 to 18.07.2017. Humboldt-Universität zu Berlin, RUD 25, Raum 3.113, Berlin, Germany (National)

Stefan Dietzel, Julian Hölzel