Technische Universität Darmstadt

About: Technische Universität Darmstadt is a education organization based out in Darmstadt, Germany. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 17316 authors who have published 40619 publications receiving 937916 citations. The organization is also known as: Darmstadt University of Technology & University of Darmstadt.

Distributed Attribute-Based Encryption

Abstract: Ciphertext-Policy Attribute-Based Encryption (CP-ABE) allows to encrypt data under an access policy, specified as a logical combination of attributes. Such ciphertexts can be decrypted by anyone with a set of attributes that fits the policy. In this paper, we introduce the concept of Distributed Attribute-Based Encryption (DABE), where an arbitrary number of parties can be present to maintain attributes and their corresponding secret keys. This is in stark contrast to the classic CP-ABE schemes, where all secret keys are distributed by one central trusted party. We provide the first construction of a DABE scheme; the construction is very efficient, as it requires only a constant number of pairing operations during encryption and decryption.

Direct Determination of Absolute Molecular Stereochemistry in Gas Phase by Coulomb Explosion Imaging

Abstract: Bijvoet's method, which makes use of anomalous x-ray diffraction or dispersion, is the standard means of directly determining the absolute (stereochemical) configuration of molecules, but it requires crystalline samples and often proves challenging in structures exclusively comprising light atoms. Herein, we demonstrate a mass spectrometry approach that directly images the absolute configuration of individual molecules in the gas phase by cold target recoil ion momentum spectroscopy after laser ionization-induced Coulomb explosion. This technique is applied to the prototypical chiral molecule bromochlorofluoromethane and the isotopically chiral methane derivative bromodichloromethane.

Heavy-ion collisions at the LHC-Last call for predictions

Abstract: This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute 'Heavy Ion Collisions at the LHC - Last Call for Predictions', held from 14th May to 10th June 2007.

Software Grand Exposure: SGX Cache Attacks Are Practical

Abstract: Side-channel information leakage is a known limitation of SGX. Researchers have demonstrated that secret-dependent information can be extracted from enclave execution through page-fault access patterns. Consequently, various recent research efforts are actively seeking countermeasures to SGX side-channel attacks. It is widely assumed that SGX may be vulnerable to other side channels, such as cache access pattern monitoring, as well. However, prior to our work, the practicality and the extent of such information leakage was not studied. In this paper we demonstrate that cache-based attacks are indeed a serious threat to the confidentiality of SGX-protected programs. Our goal was to design an attack that is hard to mitigate using known defenses, and therefore we mount our attack without interrupting enclave execution. This approach has major technical challenges, since the existing cache monitoring techniques experience significant noise if the victim process is not interrupted. We designed and implemented novel attack techniques to reduce this noise by leveraging the capabilities of the privileged adversary. Our attacks are able to recover confidential information from SGX enclaves, which we illustrate in two example cases: extraction of an entire RSA-2048 key during RSA decryption, and detection of specific human genome sequences during genomic indexing. We show that our attacks are more effective than previous cache attacks and harder to mitigate than previous SGX side-channel attacks.

Zooming Out: The Trade Effect of the Euro in Historical Perspective

Abstract: In 1999, eleven European countries formed the Economic and Monetary Union (EMU); they abandoned their national currencies and adopted a new common currency, the euro Several recent papers argue that the introduction of the euro has led (by itself) to a sizable and statistically significant increase in trade between the member countries of EMU In this paper, we put the trade effect of the euro in historical perspective We argue that the creation of the EMU was a continuation (or culmination) of a series of previous policy changes that have led over the last five decades to greater economic integration among the countries that now constitute EMU Using a data set that includes 22 industrial countries from 1948 to 2003, we find strong evidence of a gradual increase in trade intensity between European countries Once we control for this trend in trade integration, the euro's impact on trade disappears Moreover, a significant part of the trend in European trade integration is explained by measurable policy changes