Delta breakpad : diversified binary crash reporting

This paper introduces Delta Breakpad. It extends the Breakpad crash reporting system to handle software diversity effectively and efficiently by replicating and patching the debug information of diversified software versions. Simple adaptations to existing open source compiler tools are presented that on the one hand introduce significant amounts of diversification in the code and stack layout of ARMv7 binaries to mitigate the widespread deployment of code injection and code reuse attacks, while on the other hand still supporting accurate crash reporting. An evaluation on SPEC2006 benchmarks demonstrates that the corresponding computational, storage, and communication overheads are small

Saving Human Lives: What Complexity Science and Information Systems can Contribute

We discuss models and data of crowd disasters, crime, terrorism, war and disease spreading to show that conventional recipes, such as deterrence strategies, are often not effective and sufficient to contain them. Many common approaches do not provide a good picture of the actual system behavior, because they neglect feedback loops, instabilities and cascade effects. The complex and often counter-intuitive behavior of social systems and their macro-level collective dynamics can be better understood by means of complexity science. We highlight that a suitable system design and management can help to stop undesirable cascade effects and to enable favorable kinds of self-organization in the system. In such a way, complexity science can help to save human lives.Comment: 67 pages, 25 figures; accepted for publication in Journal of Statistical Physics [for related work see http://www.futurict.eu/

Obfuscated integration of software protections

To counter man-at-the-end attacks such as reverse engineering and tampering, software is often protected with techniques that require support modules to be linked into the application. It is well known, however, that attackers can exploit the modular nature of applications and their protections to speed up the identification and comprehension process of the relevant code, the assets, and the applied protections. To counter that exploitation of modularity at different levels of granularity, the boundaries between the modules in the program need to be obfuscated. We propose to do so by combining three cross-boundary protection techniques that thwart the disassembly process and in particular the reconstruction of functions: code layout randomization, interprocedurally coupled opaque predicates, and code factoring with intraprocedural control flow idioms. By means of an experimental evaluation on realistic use cases and state-of-the-art tools, we demonstrate our technique's potency and resilience to advanced attacks. All relevant code is publicly available online

Flexible software protection

To counter software reverse engineering or tampering, software obfuscation tools can be used. However, such tools to a large degree hard-code how the obfuscations are deployed. They hence lack resilience and stealth in the face of many attacks. To counter this problem, we propose the novel concept of flexible obfuscators, which implement protections in terms of data structures and APIs already present in the application to be protected. The protections are hence tailored to the application in which they are deployed, making them less learnable and less distinguishable. In our research, we concretized the flexible protection concept for opaque predicates. We designed an interface to enable the reuse of existing data structures and APIs in injected opaque predicates, we analyzed their resilience and stealth, we implemented a proof-of-concept flexible obfuscator, and we evaluated it on a number of real-world use cases. This paper presents an in-depth motivation for our work, the design of the interface, an in-depth security analysis, and a feasibility report based on our experimental evaluation. The findings are that flexible opaque predicates indeed provide strong resilience and improved stealth, but also that their deployment is costly, and that they should hence be used sparsely to protect only the most security-sensitive code fragments that do not dominate performance. Flexible obfuscation therefor delivers an expensive but also more durable new weapon in the ever ongoing software protection arms race

Geometrische studie en analyse op LBM (metaal)-geprinte balkvormen

De technologische wereld evolueert constant. 3D-printen is een techniek waarbij, naast kunststoffen, intussen in metaal solide en functionele stukken gemaakt worden. De nauwkeurigste techniek, voor stukken van relatief kleine omvang, is hier de Laser Beam Meltingtechniek, ook wel SelectiveLaser Meltinggenaamd (LBM –SLM). Om op voorhand het resultaat van 3d geprinte onderdelen in te schatten, wordt onderzoek gevoerd naar de maatvoering en afwerkingsgraad van geprinte vormen in vergelijking met het oorspronkelijke CAD model.status: publishe

Method for direct correlation of high-resolution 18F-FDG-PET/CT images with histopathology in resected breast cancer specimens

Aim/Introduction: While PET/CT imaging has become widely adopted in oncology, the distribution mechanism of one of the most common radiotracers, 18F-FDG, is not yet fully understood. To study the 18F-FDG-distribution in diferent tissue types, accurate correlation of PET/CT images with the gold standard of histopathology is required. However, correlating in vivo PET/CT images with histopathology is challenging, particularly for soft breast tissue that is extremely prone to deformation during histopathological processing. To overcome this problem, we developed a strategy to correlate ex vivo high-resolution 18F-FDG-PET/CT images of resected breast cancer specimens with histopathology with unprecedented accuracy. Materials and Methods: We used a compact PET/CT scanner with a spatial resolution of 800µm and 400µm, respectively, to acquire high-resolution PET/CT images of two breast cancer specimens obtained after breast-conserving surgery of patients who received a preoperative injection with 4MBq/kg 18F-FDG. These specimens included one invasive lobular carcinoma and one invasive ductal carcinoma, treated with neoadjuvant chemotherapy. First, a pathologist sliced the specimens into ±2mm-thick lamellas, which were enclosed in tissue cassettes. Next, high-resolution PET/CT images of the cassettes containing the lamellas were acquired. Afterwards, the tissue was processed according to the local standard protocol: (1) the lamellas were fxated and embedded in parafin while still inside the cassettes; (2) a ±5µm-thin section was obtainedfrom every lamella and (3) was H&E-stained. Finally, the pathology slides were digitized using a section scanner, and these images were digitally correlated with the PET/CT images of the lamellas. Results: PET/CT images of the fresh breast lamellas were successful in all cases. The efects of tissue deformation were minimized by using the framework of tissue cassettes. A clear correlation between the high-resolution PET/CT images and histopathology was immediately visible, allowing us to study the 18F-FDG-distribution in breast tissue at a sub-millimetric scale. In both cases, a higher 18F-FDG-uptake was detected in tumorous glandular tissue compared to healthy glandular tissue. Conclusion: We developed a novel method to correlate high-resolution 18F-FDG-PET/CT images with histopathology in resected breast cancer specimens with increased accuracy. The proposed method could provide a better understanding of 18F-FDG-distribution in healthy and tumorous breast tissue on a previously uncharted scale. To our knowledge, this is the frst time high-resolution PET/CT images of breast tissue are directly correlated with its corresponding histopathology. To further improve this correlation, mathematical co-registration algorithms will be developed to optimize the alignment between the high-resolution PET/CT images and histopathology images

Embedded BIPV module-level DC/DC converters: Classification of optimal ratings

status: Published onlin