A Verified Information-Flow Architecture

SAFE is a clean-slate design for a highly secure computer system, with pervasive mechanisms for tracking and limiting information flows. At the lowest level, the SAFE hardware supports fine-grained programmable tags, with efficient and flexible propagation and combination of tags as instructions are executed. The operating system virtualizes these generic facilities to present an information-flow abstract machine that allows user programs to label sensitive data with rich confidentiality policies. We present a formal, machine-checked model of the key hardware and software mechanisms used to dynamically control information flow in SAFE and an end-to-end proof of noninterference for this model. We use a refinement proof methodology to propagate the noninterference property of the abstract machine down to the concrete machine level. We use an intermediate layer in the refinement chain that factors out the details of the information-flow control policy and devise a code generator for compiling such information-flow policies into low-level monitor code. Finally, we verify the correctness of this generator using a dedicated Hoare logic that abstracts from low-level machine instructions into a reusable set of verified structured code generators

Secure and efficient application monitoring and replication

Memory corruption vulnerabilities remain a grave threat to systems software written in C/C++. Current best practices dictate compiling programs with exploit mitigations such as stack canaries, address space layout randomization, and control-flow integrity. However, adversaries quickly find ways to circumvent such mitigations, sometimes even before these mitigations are widely deployed. In this paper, we focus on an "orthogonal" defense that amplifies the effectiveness of traditional exploit mitigations. The key idea is to create multiple diversified replicas of a vulnerable program and then execute these replicas in lockstep on identical inputs while simultaneously monitoring their behavior. A malicious input that causes the diversified replicas to diverge in their behavior will be detected by the monitor; this allows discovery of previously unknown attacks such as zero-day exploits. So far, such multi-variant execution environments (MVEEs) have been held back by substantial runtime overheads. This paper presents a new design, ReMon, that is non-intrusive, secure, and highly efficient. Whereas previous schemes either monitor every system call or none at all, our system enforces cross-checking only for security critical system calls while supporting more relaxed monitoring policies for system calls that are not security critical. We achieve this by splitting the monitoring and replication logic into an in-process component and a cross-process component. Our evaluation shows that ReMon offers same level of security as conservative MVEEs and run realistic server benchmarks at near-native speeds

Contract-Based General-Purpose GPU Programming

Using GPUs as general-purpose processors has revolutionized parallel computing by offering, for a large and growing set of algorithms, massive data-parallelization on desktop machines. An obstacle to widespread adoption, however, is the difficulty of programming them and the low-level control of the hardware required to achieve good performance. This paper suggests a programming library, SafeGPU, that aims at striking a balance between programmer productivity and performance, by making GPU data-parallel operations accessible from within a classical object-oriented programming language. The solution is integrated with the design-by-contract approach, which increases confidence in functional program correctness by embedding executable program specifications into the program text. We show that our library leads to modular and maintainable code that is accessible to GPGPU non-experts, while providing performance that is comparable with hand-written CUDA code. Furthermore, runtime contract checking turns out to be feasible, as the contracts can be executed on the GPU

50 years of isolation

The traditional means for isolating applications from each other is via the use of operating system provided “process” abstraction facilities. However, as applications now consist of multiple fine-grained components, the traditional process abstraction model is proving to be insufficient in ensuring this isolation. Statistics indicate that a high percentage of software failure occurs due to propagation of component failures. These observations are further bolstered by the attempts by modern Internet browser application developers, for example, to adopt multi-process architectures in order to increase robustness. Therefore, a fresh look at the available options for isolating program components is necessary and this paper provides an overview of previous and current research on the area

Secure Virtualization and Multicore Platforms State-of-the-Art report

SVaM