z-Commerce: Designing a Data-Minimizing One-Click Checkout Solution

in Design Science Research for a New Society: Society 5.0 (2023)

E-commerce has grown rapidly over the past years, with prevailing e-commerce platforms aggregating large amounts of customer data. This practice has several undesirable side effects, such as facilitating ... [more ▼]

E-commerce has grown rapidly over the past years, with prevailing e-commerce platforms aggregating large amounts of customer data. This practice has several undesirable side effects, such as facilitating profiling that may lead to price discrimination and data feedback loops that can hamper competition. Moreover, data hoarding carries security risks through data breaches and undermines customers' privacy expectations. On the other hand, convenience aspects and compliance regulation demand the processing and storage of user-related data. To address this tension field, we aim to conceptualize and iteratively refine a data-minimizinig e-commerce platform. Following a design science research approach, we identify design objectives and propose and implement a solution in which stakeholders receive only customer data that is indispensable for their part of the process. Our solution leverages digital identity wallets and general-purpose zero-knowledge proofs (zk-SNARKs). We aim to perform a criteria-based evaluation to assess our artifact's feasibility and fitness from an interdisciplinary perspective. With our results, we hope to illustrate that combining state-of-the-art cryptographic techniques and an emerging digital identity paradigm allows reaching the user experience of incumbent e-commerce platforms while mitigating the undesirable socio-economic side effects of avoidable data disclosure. [less ▲]

Z4 parafermions in one-dimensional fermionic lattices

in Physical Review. B, Condensed Matter (2018), 98

Parafermions are emergent excitations which generalize Majorana fermions and are potentially relevant to topological quantum computation. Using the concept of Fock parafermions, we present a mapping ... [more ▼]

Parafermions are emergent excitations which generalize Majorana fermions and are potentially relevant to topological quantum computation. Using the concept of Fock parafermions, we present a mapping between lattice Z4-parafermions and lattice spin-1/2 fermions which preserves the locality of operators with Z4 symmetry. Based on this mapping, we construct an exactly solvable, local one-dimensional fermionic Hamiltonian which hosts parafermionic edge states. We numerically show that the parafermionic phase remains stable in a wide range of parameters, and discuss its signatures in the fermionic spectral function. [less ▲]

Z4 parafermions in time-reversal invariant topological insulators

Presentation (2015, June)

Z_2^n Supergeometry

Presentation (2014, December 17)

Z_2^n-Supergeometry II: Batchelor-Gawedzki Theorem

E-print/Working paper (2014)

Zahlen und Psychomotorik

in Motorik (2008), 2

Zak Keyes Working With…

Book published by Sternberg Press (2012)

To accompany his exhibition at the Museum of Contemporary Art Leipzig, this book presents the work of the Swiss-American graphic designer Zak Kyes. In collaboration with the curator, Barbara Steiner, the ... [more ▼]

To accompany his exhibition at the Museum of Contemporary Art Leipzig, this book presents the work of the Swiss-American graphic designer Zak Kyes. In collaboration with the curator, Barbara Steiner, the exhibition and publication bring together a range of works by Kyes, as well as works by a host of collaborators that includes architects, artists, writers, curators, editors, and graphic designers, presenting contemporary graphic design as a practice that mediates, and is mediated by, its allied disciplines. Kyes, who lives and works in London, is known for his critical approach to graphic design, which encompasses publishing, editing, and site-specific projects for and in collaboration with cultural institutions. In 2005, Kyes founded the design studio Zak Group, and, in 2006, he became Art Director of the Architectural Association (AA), London. Under the auspices of the AA, he organized the seminal touring exhibition “Forms of Inquiry: The Architecture of Critical Graphic Design,” and later cofounded Bedford Press, an imprint that seeks to develop new models for contemporary publishing. By broadening the highly specialized role of the designer, Kyes challenges and further develops today’s graphic design practice. While this work constitutes the exhibition’s point of departure, its focus is on the conceptual, visual, and economic intersections that link Kyes with his collaborators, revealing and further unfolding the designer’s multivalent practice. These intersections vary in form from idealistic to pragmatic, urgent and time-sensitive to abiding and long-lasting. Rather than presenting a chronological overview of Kyes’s work, the book highlights the designer’s relations with partners, clients, and institutions, and the creative potential of these collaborations to evolve traditional understandings of graphic design, art, and architecture. [less ▲]

ZAP

Report (2011)

Zasada rządów prawa w polityce zewnętrznej Unii Europejskiej (Rule of law in the European Union’s external policy)

in Przegląd Prawa Konstytucyjnego (Review of Constitutional Law) (2013), 2013(2), 157-175

Rule of law, whose core is „the access to an independent judiciary and judicial review”, fulfills in EU external policy two functions. Firstly, according to the art. 21 of TEU, all EU external actions ... [more ▼]

Rule of law, whose core is „the access to an independent judiciary and judicial review”, fulfills in EU external policy two functions. Firstly, according to the art. 21 of TEU, all EU external actions have to be subdued to the rule of law. Secondly, promoting and consolidating the rule of law is one the objectives of EU external action. In most constitutional systems, a wide margin of appreciation is left as regards to foreign policy and judicial review is considerably limited. In case of EU, the Court’s jurisdiction over EU external policy is differentiated and reflects the old pillar structure. The question which arises here is whether it can be accommodated with the disposition of the art. 2 of TEU, which states that the European Union which is a single legal entity „is founded on the value of rule of law”, and with the principle of EU external policy coherence. [less ▲]

Zäsur und "Stunde Null"? Personelle Brüche und Kontinuiäten in Aachen 1933 und 1945

in Der Krieg ist aus. Politik, Alltag und Medien in Aachen. (2019)