de nationalité suisse et originaire de Zurich (ZH) et Lucerne (LU) acceptée sur proposition du jury:

Abstract not found

ACKNOWLEDGMENTS I would like to give many thanks to Dr. Shengli Fu and Dr. Yan Huang as my advi-

1.1 Private and Public Key Cryptography..................... 5

Abstract not found

Commutative, idempotent groupoids and the

Implementational aspects of code-based cryptography

This paper presents the first theoretical results showing that stable identification of overcomplete µ-coherent dictionaries Φ ∈ Rd×K is locally possible from training signals with sparsity levels S up to the order O(µ−2) and signal to noise ratios up to O( d). In particular the dictionary

cell balance equations

and modulation operators. From an abstract Hilbert-space viewpoint, such sequences of functions were studied extensively in the context of stationary random processes. We thus utilize powerful tools from this discipline, although our problems are deterministic by nature. In particular, we provide necessary