Learn More
In this article we present some weaknesses in the RC4 cipher and their cryptographic applications. Especially we improve the attack described in [2] in such a way, that it will work, if the weak keys described in that paper are avoided. A further attack will work even if the first 256 Byte of the output remain unused. Finally we show that variants of the(More)
Actinoplanes sp. SE50/110 is known as the wild type producer of the alpha-glucosidase inhibitor acarbose, a potent drug used worldwide in the treatment of type-2 diabetes mellitus. As the incidence of diabetes is rapidly rising worldwide, an ever increasing demand for diabetes drugs, such as acarbose, needs to be anticipated. Consequently, derived(More)
We present improved lower bounds on the sizes of small maximal partial ovoids and small maximal partial spreads in the classical sym-plectic and orthogonal polar spaces, and improved upper bounds on the sizes of large maximal partial ovoids and large maximal partial spreads in the classical symplectic and orthogonal polar spaces. An overview of the status(More)
We start by defining generalised dual arcs, the motivation for defining them comes from cryptography, since they can serve as a tool to construct authentication codes and secret sharing schemes. We extend the charac-terisation of the tangent planes of the Veronesean surface V 4 2 in P G(5, q), q odd, described in [4], as a set of q 2 + q + 1 planes in P(More)
The pseudotetrasaccharide acarbose is a medically relevant secondary metabolite produced by strains of the genera Actinoplanes and Streptomyces. In this study gene products involved in acarbose metabolism were identified by analyzing the cytosolic and extracellular proteome of Actinoplanes sp. SE50/110 cultures grown in a high-maltose minimal medium. The(More)
Space-bounded one-way cellular language acceptors (OCA) are investigated. The only inclusion known to be strict in their time hierarchy from real-time to exponential time is between real-time and linear-time! We show the surprising result that there exists an infinite hierarchy of properly included OCA-language families in that range. A generalization of a(More)
An iterative array is a line of interconnected interacting finite automata. One distinguished automaton, the communication cell, is connected to the outside world and fetches the input serially symbol by symbol. Sometimes in the literature this model is referred to as cellular automaton with sequential input mode. We are investigating iterative arrays with(More)