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Service-centric NetworkingAxel Küpper

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Prof. Dr. Axel Küpper


Axel Küpper is a professor for Service-centric Networking at Technische Universität Berlin (TU Berlin) and Telekom Innovation Laboratories, which is a public-private partnership of Deutsche Telekom AG and TU Berlin.

Before, he was an assistant professor at the Mobile and Distributed Systems Group at Ludwig-Maximilians-Universität München, where he received his postdoctoral lecture qualification (habilitation). He graduated in computer science from RWTH Aachen University, where he also received his doctorate.

Axel's early research focused on distributed and mobile systems and networks, context-aware applications, and location-based services. In recent years, he has worked intensively on topics related to Cloud Computing, Service-oriented Architectures, and future web technologies. Axel is an advocate of decentralized systems and applications. The focus of his work here is on distributed ledger technologies, token economy, self-sovereign identity, emerging blockchain-based applications, blockchain analytics, and decentralized online social networks. 

Office hours for students

Please be informed that our office hours will be provided every Wednesday from 12:00 - 13:00.

How to find us:

Service-centric Networking, T-Labs, Ernst-Reuter-Platz 7, 10587 Berlin

Please wait at the T-Labs reception on the 18th floor.


Geocookie: a space-efficient representation of geographic location sets
Citation key RuKu2014
Author Ruppel, P. and Küpper, A.
Pages 418-424
Year 2014
DOI 10.2197/ipsjjip.22.418
Journal Journal of Information Processing (JIP)
Volume 22
Number 3
Month Jul
Editor Information Processing Society of Japan
Publisher Information Processing Society of Japan (IPSJ)
Abstract A new approach is presented that allows a user agent to compute a compact browser cookie-like character string (called Geocookie) for a third party, whereby for any given geographic location the third party can either infer that the location is definitely not covered by the Geocookie, or it can infer that the location is probably covered by the Geocookie, depending on whether the user agent has or has not included the location beforehand. The approach extends the concept of a Bloom filter and combines it with Geohashes, thus making it possible to store information about visited geographic locations in the filter. Geocookies can be used in many different scenarios for location-based queries and location-based services, whenever a user agent wants to inform a third party about a set of visited locations such that the third party can compile a result that either favors or excludes these locations. In contrast to existing approaches such as session cookies that are mapped to server-sided stored location trajectories, Geocookies provide a compact and privacy-preserving structure which does not reveal the actual set of all visited locations, but provides a one-way check function which can be used by the third party to evaluate given locations against the Geocookie. In addition, Geocookies provide plausible deniability in case of location matches. This paper introduces a formal definition for Geocookies together with a discussion on practical applications and embedding into HTTP headers.
Bibtex Type of Publication SNET
Link to publication Download Bibtex entry


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