Approximation Algorithms for Time-Constrained Scheduling on Line Networks

We consider the problem of time-constrained scheduling of packets in a communication network. Each packet has, in addition to its source and its destination, a release time and a deadline. The goal of an algorithm is to maximize the number of packets that arrive to their destinations by their respective deadlines, given the network constraints.     

Acoustic Cryptanalysis

Many computers emit a high-pitched noise during operation, due to vibration in some of their electronic components. These acoustic emanations are more than a nuisance: They can convey information about the software running on the computer and, in particular, leak sensitive information about security-related computations. In a preliminary presentation (Eurocrypt’04 rump session), we have shown that different RSA keys induce different sound patterns, but it was not clear how to extract individual key bits. The main problem was the very low bandwidth of the acoustic side channel (under 20  kHz using common microphones, and a few hundred kHz using ultrasound microphones), and several orders of magnitude below the GHz-scale clock rates of the attacked computers. In this paper, we describe a new acoustic cryptanalysis key extraction attack, applicable to GnuPG’s implementation of RSA. The attack can extract full 4096-bit RSA decryption keys from laptop computers (of various models), within an hour, using the sound generated by the computer during the decryption of some chosen ciphertexts. We experimentally demonstrate such attacks, using a plain mobile phone placed next to the computer, or a more sensitive microphone placed 10 meters away.     

On the additive constant of the k-server Work Function Algorithm

We consider the Work Function Algorithm for the k-server problem (Chrobak and Larmore, 1991; Koutsoupias and Papadimitriou, 1995) [2] and [4]. We show that if the Work Function Algorithm is c-competitive, then it is also strictly(2c)-competitive. As a consequence of (Koutsoupias and Papadimitriou, 1995) [4] this also shows that the Work Function Algorithm is strictly (4k−2)-competitive.     

New Second-Preimage Attacks on Hash Functions

In this work, we present several new generic second-preimage attacks on hash functions. Our first attack is based on the herding attack and applies to various Merkle–Damgård-based iterative hash functions. Compared to the previously known long-message second-preimage attacks, our attack offers more flexibility in choosing the second-preimage message at the cost of a small computational overhead. More concretely, our attack allows the adversary to replace only a few blocks in the original target message to obtain the second preimage. As a result, our new attack is applicable to constructions previously believed to be immune to such second-preimage attacks. Among others, these include the dithered hash proposal of Rivest, Shoup’s UOWHF, and the ROX constructions. In addition, we also suggest several time-memory-data tradeoff attack variants, allowing for a faster online phase, and even finding second preimages for shorter messages. We further extend our attack to sequences stronger than the ones suggested in Rivest’s proposal. To this end we introduce the kite generator as a new tool to attack any dithering sequence over a small alphabet. Additionally, we analyse the second-preimage security of the basic tree hash construction. Here we also propose several second-preimage attacks and their time-memory-data tradeoff variants. Finally, we show how both our new and the previous second-preimage attacks can be applied even more efficiently when multiple short messages, rather than a single long target message, are available.     

Virtual marionettes: a system and paradigm for real-time 3D animation

This paper describes a computer graphics system that enables users to define virtual marionette puppets, operate them using relatively simple hardware input devices, and display the scene from a given viewpoint on the computer screen. This computerized marionette theater has the potential to become a computer game for children, an interaction tool over the Internet, enabling the creation of simultaneously viewed and operated marionette show by users on the World Wide Web, and, most importantly, a versatile and efficient professional animation system.     

Modular Graphene‐Based 3D Covalent Networks: Functional Architectures for Energy Applications

The development of ordered graphene‐based materials combining high stability, large surface areas, ability to act as absorbent of relevant chemical species, and solution processability is of significance for energy applications. A poorly explored approach relies on the controlled nanostructuration of graphene into robust and highly ordered 3D networks as a route to further leverage the exceptional properties of this unique material. Here, a simple yet effective and scalable one‐step method is reported to prepare graphene‐based 3D covalent networks (G3DCNs) with tunable interlayer distance via controlled polymerization of benzidines with graphene oxide at different reaction temperatures under catalyst‐ and template‐free conditions. The reduced form of G3DCNs is used as electrodes in supercapacitors; it reveals a high specific capacitance of 156 F g^?1 at a current density of 1 A g^?1 in a two‐electrode configuration and 460 F g^?1 at a current density of 0.5 A g^?1 in a three‐electrode configuration, combined with an excellent cycling stability over 5000 cycles. The present study will promote the quantitative understanding of structure–property relationship, for the controlled fabrication of 3D graphene‐based multifunctional materials.     

Fast Targeting and Cancer Cell Uptake of Luminescent Antibody‐Nanozeolite Bioconjugates

Understanding the targeted cellular uptake of nanomaterials is an essential step to engineer and program functional and effective biomedical devices. In this respect, the targeting and ultrafast uptake of zeolite nanocrystals functionalized with Cetuximab antibodies (Ctxb) by cells overexpressing the epidermal growth factor receptor are described here. Biochemical assays show that the cellular uptake of the bioconjugate in the targeted cancer cells already begins 15 min after incubation, at a rate around tenfold faster than that observed in the negative control cells. These findings further show the role of Ctxb exposed at the surfaces of the zeolite nanocrystals in mediating the targeted and rapid cellular uptake. By using temperature and pharmacological inhibitors as modulators of the internalization pathways, the results univocally suggest a dissipative uptake mechanism of these nanomaterials, which seems to occur using different internalization pathways, according to the targeting properties of these nanocrystals. Owing to the ultrafast uptake process, harmless for the cell viability, these results further pave the way for the design of novel theranostic tools based on nanozeolites.     

TEM microstructural analysis of As-Bonded Al–Au wire-bonds

In this study the interface morphology of a model 99.999% (5N) Au wire bonded to Al pads in the as-bonded state was examined by scanning/transmission electron microscopy with energy dispersive spectroscopy. Specimens for transmission electron microscopy were prepared using the lift-out method in a dual-beam focused ion beam system. Analysis of the bond microstructure was conducted as a function of the Al pad content and as a function of the bonding temperature. Additions of Si and Cu to the Al pad affect the morphology and the uniformity of the interface. A characteristic-void line is formed between two intermetallic regions with different morphologies in the as-bonded samples. According to the morphological analysis it was concluded that a liquid phase forms during the bonding stage, and the void-line formed in the intermetallic region is the result of shrinkage upon solidification and not the Kirkendall effect.     

Degradation of 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT) by brown-rot fungi

Twelve species of brown-rot fungi (BRF) have been investigated for their ability to degrade 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (DDT). In potato dextrose broth (PDB) medium, Gloeophyllum trabeum, Fomitopsis pinicola and Daedalea dickinsii showed a high ability to degrade DDT. 1,1-Dichloro-2,2-bis (4-chlorophenyl) ethane (DDD), 1,1-dichloro-2,2-bis (4-chlorophenyl) ethylene (DDE) and 4,4-dichlorobenzophenone (DBP) were detected as metabolic products of DDT degradation by G. trabeum in PDB medium. The DDT degradation pathway in G. trabeum is proposed, which differs from the proposed pathways in bacteria and other fungi, particularly in the transformation of DDE to DDD. On the other hand, DBP was not detected as a metabolic product of DDT degradation in FeSO(4)-deficient cultures of G. trabeum, whereas DDE and DDD were detected, indicating the involvement of an iron-dependent reaction. Only DBP was detected from DDT, DDE and DDD degradation via a chemical Fenton reaction under conditions similar to those in G. trabeum cultures. These compounds may be directly transformed to DBP via a Fenton reaction.