A Study of Reconfigurable Accelerators for Cloud Computing

Due to the exponential increase in network traffic in the data centers, thousands of servers interconnected with high bandwidth switches are required. Field Programmable Gate Arrays (FPGAs) with Cloud ecosystem offer high performance in efficiency and energy, making them active resources, easy to program and reconfigure. This paper looks at FPGAs as reconfigurable accelerators for the cloud computing presents the main hardware accelerators that have been presented in various widely used cloud computing applications such as: MapReduce, Spark, Memcached, Databases

Laser-induced breakdown spectroscopy: a tool for real-time, in vitro and in vivo identification of carious teeth

BACKGROUND: Laser Induced Breakdown Spectroscopy (LIBS) can be used to measure trace element concentrations in solids, liquids and gases, with spatial resolution and absolute quantifaction being feasible, down to parts-per-million concentration levels. Some applications of LIBS do not necessarily require exact, quantitative measurements. These include applications in dentistry, which are of a more "identify-and-sort" nature – e.g. identification of teeth affected by caries. METHODS: A one-fibre light delivery / collection assembly for LIBS analysis was used, which in principle lends itself for routine in vitro / in vivo applications in a dental practice. A number of evaluation algorithms for LIBS data can be used to assess the similarity of a spectrum, measured at specific sample locations, with a training set of reference spectra. Here, the description has been restricted to one pattern recognition algorithm, namely the so-called Mahalanobis Distance method. RESULTS: The plasma created when the laser pulse ablates the sample (in vitro / in vivo), was spectrally analysed. We demonstrated that, using the Mahalanobis Distance pattern recognition algorithm, we could unambiguously determine the identity of an "unknown" tooth sample in real time. Based on single spectra obtained from the sample, the transition from caries-affected to healthy tooth material could be distinguished, with high spatial resolution. CONCLUSIONS: The combination of LIBS and pattern recognition algorithms provides a potentially useful tool for dentists for fast material identification problems, such as for example the precise control of the laser drilling / cleaning process

Leakier wires: exploiting FPGA long wires for covert- and side-channel attacks

In complex FPGA designs, implementations of algorithms and protocols from third-party sources are common. However, the monolithic nature of FPGAs means that all sub-circuits share common on-chip infrastructure, such as routing resources. This presents an attack vector for all FPGAs that contain designs from multiple vendors, especially for FPGAs used in multi-tenant cloud environments, or integrated into multi-core processors. In this article, we show that “long” routing wires present a new source of information leakage on FPGAs, by influencing the delay of adjacent long wires. We show that the effect is measurable for both static and dynamic signals and that it can be detected using small on-board circuits. We characterize the channel in detail and show that it is measurable even when multiple competing circuits (including multiple long-wire transmitters) are present and can be replicated on different generations and families of Xilinx devices (Virtex 5, Virtex 6, Artix 7, and Spartan 7). We exploit the leakage to create a covert channel with 6kbps of bandwidth and 99.9% accuracy, and a side channel, which can recover signals kept constant for only 1.3μs, with an accuracy of more than 98.4%. Finally, we propose countermeasures to reduce the impact of this leakage

Leakier wires: exploiting FPGA long wires for covert- and side-channel attacks

In complex FPGA designs, implementations of algorithms and protocols from third-party sources are common. However, the monolithic nature of FPGAs means that all sub-circuits share common on-chip infrastructure, such as routing resources. This presents an attack vector for all FPGAs that contain designs from multiple vendors, especially for FPGAs used in multi-tenant cloud environments, or integrated into multi-core processors. In this article, we show that “long” routing wires present a new source of information leakage on FPGAs, by influencing the delay of adjacent long wires. We show that the effect is measurable for both static and dynamic signals and that it can be detected using small on-board circuits. We characterize the channel in detail and show that it is measurable even when multiple competing circuits (including multiple long-wire transmitters) are present and can be replicated on different generations and families of Xilinx devices (Virtex 5, Virtex 6, Artix 7, and Spartan 7). We exploit the leakage to create a covert channel with 6kbps of bandwidth and 99.9% accuracy, and a side channel, which can recover signals kept constant for only 1.3μs, with an accuracy of more than 98.4%. Finally, we propose countermeasures to reduce the impact of this leakage

Leaky wires: information leakage and covert communication between FPGA long wires

Field-Programmable Gate Arrays (FPGAs) are integrated circuits that implement reconfigurable hardware. They are used in modern systems, creating specialized, highly-optimized integrated circuits without the need to design and manufacture dedicated chips. As the capacity of FPGAs grows, it is increasingly common for designers to incorporate implementations of algorithms and protocols from a range of third-party sources. The monolithic nature of FPGAs means that all on-chip circuits, including third party black-box designs, must share common on-chip infrastructure, such as routing resources. In this paper, we observe that a "long" routing wire carrying a logical 1 reduces the propagation delay of other adjacent but unconnected long wires in the FPGA interconnect, thereby leaking information about its state. We exploit this effect and propose a communication channel that can be used for both covert transmissions between circuits, and for exfiltration of secrets from the chip. We show that the effect is measurable for both static and dynamic signals, and that it can be detected using very small on-board circuits. In our prototype, we are able to correctly infer the logical state of an adjacent long wire over 99% of the time, even without error correction, and for signals that are maintained for as little as 82us. Using a Manchester encoding scheme, our channel bandwidth is as high as 6kbps. We characterize the channel in detail and show that it is measurable even when multiple competing circuits are present and can be replicated on different generations and families of Xilinx devices (Virtex 5, Virtex 6, and Artix 7). Finally, we propose countermeasures that can be deployed by systems and tools designers to reduce the impact of this information leakage

High bone turnover elevates the risk of denosumab-induced hypocalcemia in women with postmenopausal osteoporosis

Koji Ishikawa,1 Takashi Nagai,1 Keizo Sakamoto,1 Kenji Ohara,2 Takeshi Eguro,1,2 Hiroshi Ito,1 Yoichi Toyoshima,1 Akatsuki Kokaze,3 Tomoaki Toyone,1 Katsunori Inagaki1 1Department of Orthopaedic Surgery, Showa University School of Medicine, Tokyo, 2Department of Orthopaedic Surgery, Yamanashi Red Cross Hospital, Yamanashi, 3Department of Public Health, Showa University School of Medicine, Tokyo, Japan Abstract: Hypocalcemia is the most common major adverse event in patients with osteoporosis receiving the bone resorption inhibitor denosumab; however, limited information is available regarding risk factors of hypocalcemia. Therefore, this study aimed to identify the risk factors of hypocalcemia induced by denosumab treatment for osteoporosis. We retrospectively reviewed the records of patients who had received initial denosumab supplemented with activated vitamin D for osteoporosis. Serum levels of the following bone turnover markers (BTMs) were measured at baseline: bone-specific alkaline phosphatase (BAP), total N-terminal propeptide of type 1 procollagen (P1NP), tartrate-resistant acid phosphatase 5b (TRACP-5b), and urinary cross-linked N-telopeptide of type 1 collagen (NTX). Of the 85 denosumab-treated patients with osteoporosis studied, 22 (25.9%) developed hypocalcemia. Baseline serum total P1NP, TRACP-5b, and urinary NTX were significantly higher in patients with hypocalcemia than in those with normocalcemia following denosumab administration (all P<0.01). Multivariate logistic regression analysis revealed that patients with total P1NP >76.5 µg/L, TRACP-5b >474 mU/dL, or urinary NTX >49.5 nmol bone collagen equivalent/mmol creatinine had a higher risk of hypocalcemia (P<0.01). Our study suggests that denosumab may have a greater impact on serum calcium levels in patients with postmenopausal osteoporosis with higher baseline bone turnover than in patients with postmenopausal osteoporosis with normal baseline bone turnover, because maintenance of normal serum calcium in this subgroup is more dependent on bone resorption. Close monitoring of serum calcium levels is strongly recommended for denosumab-treated patients with high bone turnover, despite supplementation with activated vitamin D and oral calcium. Keywords: denosumab, hypocalcemia, bone turnover, osteoporosi