We consider the problem of constructing randomness extractors that are locally computable; that is, read only a small number of bits from their input. As recently shown by Lu (CRYPTO ‘02 ), locally computable extractors directly yield secure private-key cryptosystems in Maurer’s bounded storage model (J. Cryptology, 1992). We suggest a general “sample-then-extract” approach to constructing loca...

Randomness extractors are an important building block for classical and quantum cryptography. However, for many applications it is crucial that the extractors are quantum-proof, i.e., that they work even in the presence of quantum adversaries. In general, quantum-proof extractors are poorly understood and we would like to argue that in the same way as Bell inequalities (multi prover games) and ...

We present a negative result of fuzzy extractors with computational security. Specifically, we show that, under a certain computational condition, the existence of a computational fuzzy extractor implies the existence of an information-theoretic fuzzy extractor with slightly weaker parameters. The condition is that the generation procedure of the fuzzy extractor is efficiently invertible by an ...

Let V ⊆ [n] be a k-element subset of [n]. The uniform distribution on the 2k strings from {0, 1}n that are set to zero outside is called an (n, k)-zero-fixing source. An ϵ-extractor for sources mapping F: → 1}m, some m, such F(X) ϵ-close in statistical distance 1}m every source X. Zero-fixing were introduced by Cohen and Shinkar [7] connection with previously studied extractors bit-fixing sourc...

We report on the Penn State team’s experience in the CHEMDNER chemical entity mention and the chemical document indexing tasks. Our approach devises a probabilistic framework that incorporates an ensemble of multiple information extractors to obtain high accuracy. The probabilistic framework can be configured to optimize for either precision, recall, or F-Measure based on the task requirement. ...

Randomness extractors, widely used in classical and quantum cryptography and other fields of computer science, e.g., derandomization, are functions which generate almost uniform randomness from weak sources of randomness. In the quantum setting one must take into account the quantum side information held by an adversary which might be used to break the security of the extractor. In the case of ...