SecureJS Compiler: Portable Memory Isolation in JavaScript

International audienceThe memory isolation mechanism plays an essential role to provide security enforcement in JavaScript programs. Existing secure interaction libraries such as Google Caja, SES, and VM2 rely on built-in memory isolation mechanisms provided by Node.js and browsers, yet most of the other engines such as JerryScript and Duktape, which are implementations for IoT devices, do not support such isolation mechanisms.In this paper, we report about the design and implementation of SecureJS, a portable JavaScript-to-JavaScript compiler that enforces memory isolation. As it only uses standard features, the compiled code it generates can be used by any JavaScript engine. We validated empirically the semantics preservation and memory isolation of SecureJS compiled programs by using 10,490 test programs of ECMAScript Test262 test suite. We also developed a novel experiment to evaluate memory isolation property of compiled code by instrumented JavaScript engines

Micro-Jet Test Facility for Aerospace Propulsion Engineering Education

This paper describes the methodology that has been developed and implemented at the School ofAeronautics (ETSIA) of the Universidad Politecnica de Madrid (UPM) to familiarize aerospaceengineering students with the operation of real complex jet engine systems. This methodology has atwo-pronged approach: students carry out preparatory work by using, first, a gas turbineperformance prediction numerical code; then they validate their assumptions and results on anexperimental test rig. When looking at the educational aspects, we have taken care that, apart frombeing sufficiently robust and flexible, the experimental set-up is similar to real jet engine rigs, so thestudents are not constrained to exploring a much too limited parametric space. Also, because afacility like this is usually subject to extensive and somewhat rugged use, we have focused on a lowcost design

Data Logging System for a Synthetic Aperture Radar Unit

A small, existing radar unit lacked the ability to automatically store the data it was receiving, which made its use clunky and cumbersome. A system was constructed to allow an on-board microprocessor to track distance traveled, and automatically store the data output from the radar unit to a portable memory unit for later data processing. Distance traveled is determined using a specially designed mobile cart, which electronically converts the rotation of a wheel into an electrical signal while also providing stability for taking accurate radar measurements. The output data from the radar unit is stored as a properly-formatted sound file to allow for immediate data analysis

A Secure Traitor Tracing Scheme against Key Exposure

Copyright protection is a major issue in distributing digital content. On the other hand, improvements to usability are sought by content users. In this paper, we propose a secure {\it traitor tracing scheme against key exposure (TTaKE)} which contains the properties of both a traitor tracing scheme and a forward secure public key cryptosystem. Its structure fits current digital broadcasting systems and it may be useful in preventing traitors from making illegal decoders and in minimizing the damage from accidental key exposure. It can improve usability through these properties.Comment: 5 pages, IEEE International Symposium on Information Theory 2005 (ISIT 2005

Improvement of Memory Characteristics of Charge-Trapping Memory Device by Using HfO2_2/Al2_2O3_3 Laminate

Current portable memory device relies heavily on flash memory technology for its implementation. New generation of non-volatile memory is likely to replace floating gates, charge-trapping memory currently still suffering from inadequate retention performance and slow programming speeds as well as small memory window. In contrast, the use of HfO$_2$/Al$_2$O$_3$ stacked high-k materials has substantially increased the memory window of memory devices, with a 63% increase relative to pure HfO$_2$ materials. The current goal of up to 80% retention characteristics over a ten-year period has been achieved by adjusting the deposition ratio or dopant material. Process conditions can continue to be investigated in the future to reduce charge loss while maintaining the increased memory window

CPUとGPU間のデータ転送時間の短縮に関する研究

近年、GPUを利用して一般的な並列プログラミングを行う手法は、高性能コンピューティングでよく見られる方法である。また、NVIDIA社のCUDAに代表されるGPU向けの開発環境が整備され、元々汎用的なプログラムの記述が困難であるGPU向けのプログラミングも手軽に行えるようになった。しかし、GPUで演算するためには、CPUとGPU間のデータ転送が必要であり、計算時間よりもデータの転送時間が大きい場合がある。CUDA2.2では、Memory Copy以外のデータ転送方式Zero Copy方式を用意した。データがCPU上のMapped Memoryに保存され、メモリのアドレス空間をCPUとGPU間でマッピングすることにより、GPUがCPUのメモリ上のデータを直接アクセスすることができ、CPUとGPU間のデータ転送時間の短縮が期待される。しかし、Zero Copy方式を使う際に、GPU側のメモリ内に保存されていないデータへのアクセス回数が多い場合、逆に性能が落ちる可能性がある。本研究では、CPUとGPU間のデータ転送時間の短縮を目指し、データアクセス回数を基づいて適切なデータ転送方式の選択手法を提案する。アクセス回数が2回以上のデータだけGPU側のメモリにMemory Copyにより転送してアクセスし、アクセス回数が1回のデータについてはZero Copy方式により転送する。さらに本研究では、Zero Copy方式のメモリ領域確保の方法と通常のデータ転送と違うため、コードの変更が必要となり、プログラマの負担となっている一点に着目し、より容易にデータ転送方式を変更できるCUDA APIを提案する。APIはプログラマの選択により、各データのメモリ領域申請や、必要に応じてデータ転送や、メモリ領域の解放などを自動的に行う。k-Nearest Neighbors問題の評価実験によって実行時間の比較を行った結果、提案したデータ転送方式と従来データ転送方式に比べて12%の実行時間の短縮ができた。また、API使用前後の実行時間の比較により、API使用時のオーバーヘッドは十分小さいことが示した。電気通信大学201