University of Mannheim

About: University of Mannheim is a education organization based out in Mannheim, Germany. It is known for research contribution in the topics: Population & European union. The organization has 4448 authors who have published 12918 publications receiving 446557 citations. The organization is also known as: Uni Mannheim & UMA.

Time-varying credit risk and liquidity premia in bond and CDS markets

Abstract: We develop a reduced-form model that allows us to decompose bond spreads and CDS premia into a pure credit risk component, a pure liquidity component, and a component measuring the relation between credit risk and liquidity. CDS liquidity has important consequences for the bond credit risk and liquidity components. Besides the credit risk link, we document a liquidity link between the bond and the CDS market. Liquidity in both markets dries up as credit risk increases, and higher bond market liquidity leads to lower CDS market liquidity. Ignoring CDS liquidity results in partly negative liquidity premia, particularly when CDS liquidity is low.

How Context Matters? Mobilization, Political Opportunity Structures, and Nonelectoral Political Participation in Old and New Democracies:

Abstract: Scholars have long argued that political participation is determined by institutional context. Within the voter turnout literature, the impact of various institutional structures has been demonstrated in numerous studies. Curiously, a similar context-driven research agenda exploring the correlates of nonelectoral participation (NEP) has not received the same attention. This study addresses this lacuna by testing a political opportunity structure (POS) model of citizen activism across 24 old and new democracies using International Social Survey Programme 2004: Citizenship (ISSP 2004) data. Using a multilevel modeling approach, this study tests a competition versus consensus conception of how decentralized institutions determine NEP. This research demonstrates that states with more competitive veto points operating through systems of horizontal and territorial decentralization increase individual NEP. In addition, it interacts with social mobilization networks to promote greater citizen activism: Institutio...

Education and Youth Integration into European Labour Markets

Abstract: Education is a crucial determinant of people’s life chances, and it particularly affects the integration of youth into labour markets. The article shows how different kinds and levels of education shape the access of young people to jobs of varying advantage and the smoothness of the transition from school to work. It elaborates the common patterns in the relationship between education and early career labour market outcomes and investigates - especially for EU member countries - how varying institutional arrangements in the educational systems and in the regulation of labour markets lead to varying integration outcomes.

A security framework for the analysis and design of software attestation

Abstract: Software attestation has become a popular and challenging research topic at many established security conferences with an expected strong impact in practice. It aims at verifying the software integrity of (typically) resource-constrained embedded devices. However, for practical reasons, software attestation cannot rely on stored cryptographic secrets or dedicated trusted hardware. Instead, it exploits side-channel information, such as the time that the underlying device needs for a specific computation. As traditional cryptographic solutions and arguments are not applicable, novel approaches for the design and analysis are necessary. This is certainly one of the main reasons why the security goals, properties and underlying assumptions of existing software attestation schemes have been only vaguely discussed so far, limiting the confidence in their security claims. Thus, putting software attestation on a solid ground and having a founded approach for designing secure software attestation schemes is still an important open problem.We provide the first steps towards closing this gap. Our first contribution is a security framework that formally captures security goals, attacker models and various system and design parameters. Moreover, we present a generic software attestation scheme that covers most existing schemes in the literature. Finally, we analyze its security within our framework, yielding sufficient conditions for provably secure software attestation schemes. We expect that such a consolidating work allows for a meaningful security analysis of existing schemes, supports the design of secure software attestation schemes and will inspire new research in this area.

BDD-Based Cryptanalysis of Keystream Generators

Abstract: 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 some nonlinear compression function We present an nO(1)2(1-?)/(1+?)n time bounded attack, the FBDD-attack, against LFSR-based generators, which computes the secret initial state x ? {0, 1}n from cn consecutive keystream bits, where a denotes the rate of information, which C reveals about the internal bitstream, and c denotes some small constant The algorithm uses Free Binary Decision Diagrams (FBDDs), a data structure for minimizing and manipulating Boolean functions The FBDD-attack yields better bounds on the effective key length for several keystream generators of practical use, so a 0656n bound for the self-shrinking generator, a 06403n bound for the A5/1 generator, used in the GSM standard, a 06n bound for the E0 encryption standard in the one level mode, and a 08823n bound for the two-level E0 generator used in the Bluetooth wireless LAN system