ERC Starting Grants for Tobias Vogl and Violetta Weger

Since scattering and absorption are significant only in the lowest ten kilometers of the atmosphere, satellites could enable long-distance quantum communication in the future. However, satellite-based quantum communication faces certain limitations: The satellites use only weak lasers, which results in a low data rate. In addition, quantum information can only be transmitted at night. The QUCONAT project aims to overcome these hurdles. To this end, the team led by Prof. Tobias Vogl is developing a compact single-photon source that specifically generates individual photons and functions even under space conditions. A special filter is designed to distinguish the quantum signal from sunlight, even in daylight. This will also significantly increase the effective data rate. As a result, smaller satellites could establish secure quantum connections in the future and provide key building blocks for a European quantum internet. Mobile systems for direct connections within cities are also conceivable.

Tobias Vogl is a professor of Quantum Communication Systems Engineering at the TUM School of Computation, Information and Technology.

Quantum computers pose a fundamental challenge to modern cryptography: many of the mathematical problems underlying today's encryption and signature schemes could be solved efficiently by sufficiently powerful quantum computers. New quantum-resistant cryptographic systems are therefore being developed and standardized worldwide. One promising alternative is code-based cryptography, whose security relies on difficult problems from the mathematical theory of error-correcting codes.

In her project CODES – Cryptanalysis Of Decoding, Equivalence and Algebraic Structure, Prof. Violetta Weger investigates the mathematical foundations of this security. The project focuses on three fundamental problems: decoding general codes, determining when two codes are equivalent, and detecting hidden algebraic structure. CODES aims to understand more precisely how difficult these problems really are and which mathematical properties can be exploited in cryptographic attacks. By developing new methods at the intersection of algebra, coding theory, and combinatorics, the project seeks to provide a stronger mathematical basis for assessing the security of future post-quantum cryptographic systems.

Violetta Weger is a Rudolf Mößbauer Tenure Track Professor of Applied Algebra at the TUM School of Computation, Information and Technology.