University of Passau

About: University of Passau is a education organization based out in Passau, Bayern, Germany. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 1543 authors who have published 4763 publications receiving 93338 citations.

Rigorous examination of reactive systems

Abstract: The goal of the RERS challenge is to evaluate the effectiveness of various verification and validation approaches on reactive systems, a class of systems that is highly relevant for industrial critical applications. The RERS challenge brings together researchers from different areas of software verification and validation, including static analysis, model checking, theorem proving, symbolic execution, and testing. The challenge provides a forum for experimental comparison of different techniques on specifically designed verification tasks. These benchmarks are automatically synthesized to exhibit chosen properties, and then enhanced to include dedicated dimensions of difficulty, such as conceptual complexity of the properties (e.g., reachability, safety, liveness), size of the reactive systems (a few hundred lines to millions of lines), and complexity of language features (arrays and pointer arithmetic). The STTT special section on RERS describes the results of the evaluations and the different analysis techniques that were used in the RERS challenges 2012 and 2013.

A simulation framework for Virtual Network Embedding algorithms

Abstract: Network virtualization is seen as an enabling technology for the Future Internet. In this context, many Virtual Network Embedding algorithms have been introduced in literature so far. This paper di ...

The point density measure in the quantization of self-similar probabilities

Abstract: Let P be the self-similar probability corresponding to an iterated function system of contracting similitudes S1, . . . , SN with probabilities p1, . . . , pN and contraction constants s1, . . . , sN . LetDr be the quantization dimension of P of order r ∈ (0,+∞), and let Pr be the self-similar probability corresponding to S1, . . . , SN with probabilities (p1s r 1) Dr /(r+Dr , . . . , (pNs r N ) Dr /(r+Dr . It is shown that the quanitzation coefficient of P of order r exists and that the empirical measures on an arbitrary sequence of asymptotically optimal quantizing sets (of order r) weakly converges to Pr provided log(p1s r 1), . . . , log (pNs r N ) is not arithmetic and S1, . . . , SN satisfies the open set condition.

Analysis of NORX: Investigating Differential and Rotational Properties

Abstract: This paper presents a thorough analysis of the AEAD scheme NORX, focussing on differential and rotational properties. We first introduce mathematical models that describe differential propagation with respect to the non-linear operation of NORX. Afterwards, we adapt a framework previously proposed for ARX designs allowing us to automatise the search for differentials and characteristics. We give upper bounds on the differential probability for a small number of steps of the NORX core permutation. For example, in a scenario where an attacker can only modify the nonce during initialisation, we show that characteristics have probabilities of less than \(2^{-60}\) (\(32\)-bit) and \(2^{-53}\) (\(64\)-bit) after only one round. Furthermore, we describe how we found the best characteristics for four rounds, which have probabilities of \(2^{-584}\) (\(32\)-bit) and \(2^{-836}\) (\(64\)-bit), respectively. Finally, we discuss some rotational properties of the core permutation which yield some first, rough bounds and can be used as a basis for future studies.

Accountable Redactable Signatures

Abstract: Redact able signature schemes (RSS) allow removing blocks from signed data. State-of-the-art schemes have public redactions, i.e., Any party can remove parts from a signed message. This prohibits meaningful definitions of accountability. We address this gap by introducing the notion of accountable redact able signature schemes (ARSS). We present a generic construction which couples a sanitizable signature scheme (SSS) to profit from its accountability with an RSS to maintain the reduced malleability of RSSs. Depending on the building blocks, the resulting scheme offers transparency or public accountability. Transparency provides stronger privacy guarantees, while public accountability meets legal and application requirements.