All reports by Author Matthias Krause:

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TR01-078
| 6th November 2001
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Matthias Krause#### BDD-based Cryptanalysis of Keystream Generators

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TR00-014
| 16th February 2000
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Matthias Krause, Stefan Lucks#### On Learning versus Distinguishing and the Minimal Hardware Complexity of Pseudorandom Function Generators

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TR00-003
| 26th November 1999
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Matthias Krause, Hans Ulrich Simon#### Determining the Optimal Contrast for Secret Sharing Schemes in Visual Cryptography

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TR99-011
| 14th April 1999
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Matthias Krause, Petr Savicky, Ingo Wegener#### Approximations by OBDDs and the variable ordering problem

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TR95-009
| 2nd February 1995
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Matthias Krause#### A note on realizing iterated multiplication by small depth threshold circuits

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TR94-023
| 12th December 1994
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Matthias Krause, Pavel Pudlak#### On the Computational Power of Depth 2 Circuits with Threshold and Modulo Gates

Matthias Krause

Many of the keystream generators which are used in practice are LFSR-based in the sense

that they produce the keystream according to a rule $y=C(L(x))$,

where $L(x)$ denotes an internal linear bitstream, produced by a small number of parallel

linear feedback shift registers (LFSRs),

and $C$ denotes ...
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Matthias Krause, Stefan Lucks

\begin{abstract}

A set $F$ of $n$-ary Boolean functions is called a pseudorandom function generator

(PRFG) if communicating

with a randomly chosen secret function from $F$ cannot be

efficiently distinguished from communicating with a truly random function.

We ask for the minimal hardware complexity of a PRFG. This question ...
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Matthias Krause, Hans Ulrich Simon

This paper shows that the largest possible contrast C(k,n)

in a k-out-of-n secret sharing scheme is approximately

4^(-(k-1)). More precisely, we show that

4^(-(k-1)) <= C_{k,n} <= 4^(-(k-1))}n^k/(n(n-1)...(n-(k-1))).

This implies that the largest possible contrast equals

4^(-(k-1)) in the limit when n approaches ...
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Matthias Krause, Petr Savicky, Ingo Wegener

Ordered binary decision diagrams (OBDDs) and their variants

are motivated by the need to represent Boolean functions

in applications. Research concerning these applications leads

also to problems and results interesting from theoretical

point of view. In this paper, methods from communication

complexity and ...
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Matthias Krause

It is shown that decomposition via Chinise Remainder does not

yield polynomial size depth 3 threshold circuits for iterated

multiplication of n-bit numbers. This result is achieved by

proving that, in contrast to multiplication of two n-bit

numbers, powering, division, and other related problems, the

...
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Matthias Krause, Pavel Pudlak

We investigate the computational power of depth two circuits

consisting of $MOD^r$--gates at the bottom and a threshold gate at

the top (for short, threshold--$MOD^r$ circuits) and circuits with

two levels of $MOD$ gates ($MOD^{p}$-$MOD^q$ circuits.) In particular, we

will show the following results

(i) For all prime numbers ... more >>>