Forschung: Professur für Coding and Cryptography

Coding Theory

The COD group is working on coding theory and its applications. Our research considers code constructions, decoding algorithms, and combinatorial properties. We deal with classical codes such as Reed-Solomon and BCH codes, as well as with coding in other metrics, e.g., the rank metric, the cover metric, and the Levenshtein metric.

One aspect of our work is list decoding which is a powerful technique for increasing the error correcting capability of codes. A list decoder returns not only a unique decoding result, but all codewords in a certain radius around the received word. In pratical applications, list decoding is frequently used in concatenated coding schemes.

Currently working in this area:

  • Haider Al-Kim
  • Anisha Banerjee
  • Anna Baumeister
  • Lukas Holzbaur
  • Andreas Lenz
  • Hedongliang Liu
  • Luis Maßny
  • Georg Maringer
  • Vivian Papadopoulou
  • Julian Renner
  • Hugo Sauerbier Couvée
  • Lorenz Welter
  • Marvin Xhemrishi
  • Rawad Bitar
  • Serge Kas Hanna
  • Violetta Weger
  • Yonatan Yehezkeally
  • Antonia Wachter-Zeh

Students:

  • Maximilian Egger (Master's Thesis)
  • Gökberk Erdoğan (Master's Thesis)
  • Ana Lomashvili (Master's Thesis)
  • Georg Griessing (Research Internship)
  • Anmoal Porwal (Master's Thesis)
  • Anirudh Ramesh (Research Internship)
  • Leopold Thomas (Research Internship)

Coding for Distributed Data Storage and Memories

Data storage media like flash memories (used in USB flash drives or solid state drives) suffer from manufacturing imperfections, wearout, and fluctuating read/write errors. In cloud storage systems with distributed data storage, it is necessary to design coding solutions in order to cope with failures of data servers.

Currently working in this area:

  • Haider Al Kim
  • Lukas Holzbaur
  • Andreas Lenz
  • Hedongliang Liu
  • Rawad Bitar
  • Yonatan Yehezkeally
  • Antonia Wachter-Zeh
  • Eitan Yaakobi

Students:

Private Information Retrieval

Data retrieval from a data base shared by many users is a common occurrence in online services (e.g., Netflix, YouTube,...). Privacy protection regulations pose new challenges for providers of such services. Private Information Retrieval offers coding solutions that hide the identity of the file a user desires, while minimizing the communication overhead

Currently working in this area:

  • Lukas Holzbaur
  • Antonia Wachter-Zeh

Students:

Private and Secure Coded Computation

In distributed computing, the master is interested in computing complex tasks, which can be done by hiring external workers and splitting the computation into smaller tasks. The tasks are distributed to the workers that can run the computation in parallel, i.e., independent from each other. However, the presence of slow processing nodes, known as stragglers, can outweigh the benefits of parallelism. Moreover, the data involved into computation can be sensitive, in the sense that its leak can harm the owner. Thus, private and secure coded computation uses coding theory techniques to guarantee privacy against a group of workers that share information among each other to extract information about the dataset, secrecy against adversarial workers that try to affect the computation in their behalf and resiliency against straggler nodes. 

Currently working in this area:

  • Christoph Hofmeister
  • Luis Maßny
  • Vivian Papadopoulou
  • Marvin Xhemrishi
  • Rawad Bitar
  • Antonia Wachter-Zeh

Students:

 

Network Coding

The principle of network coding has been attracting growing attention in the recent years as a technique to disseminate information in data networks, due to the higher achievable throughput compared to routing. In routing, the packets are forwarded at each node of the network, whereas in (linear) network coding, the nodes perform linear combinations of all packets received so far. Fundamental questions in the area of network coding include assigning appropriate linear combinations to the nodes and choosing a suitable error-correcting code for the case when packets are lost or adversaries inject erroneous packets.

Currently working in this area:

  • Hedongliang Liu
  • Antonia Wachter-Zeh

Students:

Coded Caching

In a broadcast or multicast senario, local caching has been regarded as an efficient approach to reduce congestions in the senario that large number of users request different files at the same time. Coded caching is a study to further reduce the transmission delay by designing the cached data and the transmitting data with coding strategies. These techniques are potentially used in live streaming, airline media and content sharing platform (e.g., Facebook, Instagram, TikTok), etc.

Currently working in this area:

  • Hedongliang Liu
  • Mari Kobayashi
  • Antonia Wachter-Zeh

Students:

Post Quantum Cryptography

The realistic threat of a quantum supercomputer has motivated research on post-quantum cryptography. Assuming an attack of a sufficiently large quantum computer, several classical public-key algorithms as RSA become insecure since computationally intensive mathematical problems become easy-to-solve. It is therefore necessary to design techniques which are secure against an attack of a quantum computer. One approach to achieve this security is code-based cryptography, where encryption and decryption is based on encoding and decoding an algebraic code. The COD group investigates and improves post-quantum cryptographic systems. Other security-related topics of our group include physical unclonable functions.

Currently working in this area:

  • Anna Baumeister
  • Thomas Jerkovits
  • Hedongliang Liu
  • Georg Maringer
  • Sabine Pircher
  • Julian Renner
  • Hugo Sauerbier Couvée
  • Violetta Weger
  • Antonia Wachter-Zeh

Students:

  • Julia Mader (Research Internship)
  • Emre Özbaş (Research Internship)
  • Stefan Ritterhoff (Research Internship)

Coding for DNA Storage

Data Storage in synthesized DNA is a novel approach for long-term data storage motivated by the high storage density and durability. Due to biological processes this requires codes that correct special errors such as insertions, deletions, duplications and other errors.

Currently working in this area:

  • Anisha Banerjee
  • Andreas Lenz
  • Lorenz Welter
  • Rawad Bitar
  • Serge Kas Hanna
  • Yonatan Yehezkeally
  • Antonia Wachter-Zeh
  • Eitan Yaakobi
  • Students:
  • Omar El Khouly (Research Internship)
  • Natalija Nikolic (Master's Thesis)
  • Felix Schäfer (Research Internship)
  • Evagoras Stylianou (Hiwi)

Funding Organisations

The COD group receives funding from the following organisations:

  • Technical University of Munich (TUM)
  • European Research Council (ERC)
  • German Research Foundation (DFG)
  • Federal Ministry of Education and Research (BMBF)
  • Institute for Advanced Study of TUM (IAS)
  • German Academic Exchange Service (DAAD)
  • Alexander von Humboldt Foundation (AvH, Postdoctoral Fellowship for Yonatan Yehezkeally)