Forschung: Professur für Coding for Communications and Data Storage

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:

  • Lukas Holzbaur
  • Andreas Lenz
  • Hedongliang Liu
  • Haider Al-Kim
  • Lorenz Welter
  • Georg Maringer
  • Julian Renner
  • Marvin Xhemrishi
  • Rawad Bitar
  • Alessandro Neri
  • Nikita Polianskii
  • Antonia Wachter-Zeh

Students:

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
  • Nikita Polianskii
  • Rawad Bitar
  • Alessandro Neri
  • Camilla Hollanti
  • Eitan Yaakobi
  • Antonia Wachter-Zeh

Students:

  • Benjamin Koh Yongjie (Bachelor's Thesis)
  • Minhan Gao (Master's Thesis)

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
  • Camilla Hollanti
  • 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:

  • 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:

  • Minhan Gao (Research Internship)

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:

  • Georg Maringer
  • Julian Renner
  • Hedongliang Liu
  • Sabine Pircher
  • Thomas Jerkovits
  • Antonia Wachter-Zeh

Students:

  • Michelle Kreisel (Hiwi)
  • Johannes Kunz (Bachelor's Thesis)

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:

  • Andreas Lenz
  • Lorenz Welter
  • Nikita Polianskii
  • Rawad Bitar
  • Eitan Yaakobi
  • Antonia Wachter-Zeh

Students:

  • Felix Kruse (Master's Thesis)
  • Anisha Banerjee (Master's Thesis)
  • Yixuan Yan (Master's Thesis)