330 research outputs found
Data assurance in opaque computations
The chess endgame is increasingly being seen through the lens of, and therefore effectively defined by, a data âmodelâ of itself. It is vital that such models are clearly faithful to the reality they purport to represent. This paper examines that issue and systems engineering responses to it, using the chess endgame as the exemplar scenario. A structured survey has been carried out of the intrinsic challenges and complexity of creating endgame data by reviewing the past pattern of errors during work in progress, surfacing in publications and occurring after the data was generated. Specific measures are proposed to counter observed classes of error-risk, including a preliminary survey of techniques for using state-of-the-art verification tools to generate EGTs that are correct by construction. The approach may be applied generically beyond the game domain
Kranc: a Mathematica application to generate numerical codes for tensorial evolution equations
We present a suite of Mathematica-based computer-algebra packages, termed
"Kranc", which comprise a toolbox to convert (tensorial) systems of partial
differential evolution equations to parallelized C or Fortran code. Kranc can
be used as a "rapid prototyping" system for physicists or mathematicians
handling very complicated systems of partial differential equations, but
through integration into the Cactus computational toolkit we can also produce
efficient parallelized production codes. Our work is motivated by the field of
numerical relativity, where Kranc is used as a research tool by the authors. In
this paper we describe the design and implementation of both the Mathematica
packages and the resulting code, we discuss some example applications, and
provide results on the performance of an example numerical code for the
Einstein equations.Comment: 24 pages, 1 figure. Corresponds to journal versio
Experience with statically-generated proxies for facilitating Java runtime specialisation
Issues pertaining to mechanisms which can be used to change the behaviour of Java classes at runtime are discussed. The proxy mechanism is compared to, and contrasted with other standard approaches to this problem. Some of the problems the proxy mechanism is subject to are expanded upon. The question of whether statically-developed proxies are a viable alternative to bytecode rewriting was investigated by means of the JavaCloak system, which uses statically-generated proxies to alter the runtime behaviour of externally-developed code. The issues addressed include ensuring the type safety, dealing with the self problem, object encapsulation, and issues of object identity and equality. Some performance figures are provided which demonstrate the load the JavaCloak proxy mechanism places on the system
When a Patch is Not Enough - HardFails: Software-Exploitable Hardware Bugs
In this paper, we take a deep dive into microarchitectural security from a
hardware designer's perspective by reviewing the existing approaches to detect
hardware vulnerabilities during the design phase. We show that a protection gap
currently exists in practice that leaves chip designs vulnerable to
software-based attacks. In particular, existing verification approaches fail to
detect specific classes of vulnerabilities, which we call HardFails: these bugs
evade detection by current verification techniques while being exploitable from
software. We demonstrate such vulnerabilities in real-world SoCs using RISC-V
to showcase and analyze concrete instantiations of HardFails. Patching these
hardware bugs may not always be possible and can potentially result in a
product recall. We base our findings on two extensive case studies: the recent
Hack@DAC 2018 hardware security competition, where 54 independent teams of
researchers competed world-wide over a period of 12 weeks to catch inserted
security bugs in SoC RTL designs, and an in-depth systematic evaluation of
state-of-the-art verification approaches. Our findings indicate that even
combinations of techniques will miss high-impact bugs due to the large number
of modules with complex interdependencies and fundamental limitations of
current detection approaches. We also craft a real-world software attack that
exploits one of the RTL bugs from Hack@DAC that evaded detection and discuss
novel approaches to mitigate the growing problem of cross-layer bugs at design
time
GPU-Based One-Dimensional Convolution for Real-Time Spatial Sound Generation
Incorporating spatialized (3D) sound cues in dynamic and interactive videogames and immersive virtual environment applications is beneficial for a number of reasons, ultimately leading to an increase in presence and immersion. Despite the benefits of spatial sound cues, they are often overlooked in videogames and virtual environments where typically, emphasis is placed on the visual cues. Fundamental to the generation of spatial sound is the one-dimensional convolution operation which is computationally expensive, not lending itself to such real-time, dynamic applications. Driven by the gaming industry and the great emphasis placed on the visual sense, consumer computer graphics hardware, and the graphics processing unit (GPU) in particular, has greatly advanced in recent years, even outperforming the computational capacity of CPUs. This has allowed for real-time, interactive realistic graphics-based applications on typical consumer- level PCs. Given the widespread use and availability of computer graphics hardware and the similarities that exist between the fields of spatial audio and image synthesis, here we describe the development of a GPU-based, one-dimensional convolution algorithm whose efficiency is superior to the conventional CPU-based convolution method. The primary purpose of the developed GPU-based convolution method is the computationally efficient generation of real- time spatial audio for dynamic and interactive videogames and virtual environments
Hamburger Helper Recipes
Hamburger Helper Recipes is a collection of essays and public addresses that aim to recuperate castoff and misfit material surrounding industries and tools which produce science-fiction fantasies, specifically videogames and television shows. The following essays confront the normative violence of capitalism, whiteness, and hetero-patriarchy that socially and technologically haunt these imaginary worlds and build hegemonic idealogy into their audiences. This collection takes industrial materials and software from their intended commercial purposes of production and âsuccessâ into places of abjection and quiet breakdown. The authorâs own proximity to masculine and often toxic work cultures\u27\u27 within industrial spaces of coding and manufacturing has informed a practice of humor and play based in a conflicted love for industrial material. As it looks critically inward and outward from its own positionality, Hamburger Helper Recipes oscillates in relation to the inside or outside of that which is âstandardâ. The notion of a queer operative within these spaces is proposed as an undercover catalyst for the reimagination of these tools into tender co-conspirators or facilitators charged to break down taboo barriers imposed by normative, capitalist culture and model new relationships between individuals and collectives
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