The Experts below are selected from a list of 84 Experts worldwide ranked by ideXlab platform
Brent Byunghoon Kang - One of the best experts on this subject based on the ideXlab platform.
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S-OpenSGX: A system-level platform for exploring SGX enclave-based computing
Computers & Security, 2017Co-Authors: Changho Choi, Nohyun Kwak, Jinsoo Jang, Daehee Jang, Kyungsoo Kwag, Brent Byunghoon KangAbstract:Abstract Intel recently introduced Software Guard Extensions (SGX) to enable applications to protect their selected code and data from privileged platform software. As it draws wider attention from the security research community, an open-source emulator for SGX (OpenSGX) has been developed to allow researchers to explore the SGX environment. To the best of our knowledge, OpenSGX is currently the only publicly available SGX emulation platform; however, its system-level support is largely limited owing to its user-mode emulation. In particular, experiments that require system functionalities or device emulation cannot be conducted with the current OpenSGX. To solve this problem, we propose System-OpenSGX (S-OpenSGX), which leverages QEMU's system emulation to provide researchers with full system-level support for exploring SGX enclave-based programming. In this paper, we show the design of S-OpenSGX, including system functionalities such as scheduling, multithreading, page table handling, and SGX paging. Non-trivial issues derived from the difference between user-mode and system emulation, and our approaches to addressing them are also described. Lastly, we utilize S-OpenSGX to experiment with a new mitigation method against the data leaking attack on enclave threads and an APIC (Advanced programmable interrupt controller) device modification to reduce SGX's mode switch overhead.
Mário César Ugulino De Araújo - One of the best experts on this subject based on the ideXlab platform.
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An inexpensive, portable and microcontrolled near infrared LED-photometer for screening analysis of gasoline.
Talanta, 2007Co-Authors: Edvaldo N. Gaião, Sérgio R. B. Santos, Vagner Bezerra Dos Santos, Elaine Cristina Lima Do Nascimento, Renato S. Lima, Mário César Ugulino De AraújoAbstract:A microcontrolled, portable and inexpensive photometer is proposed. It uses a near infrared light emitting diode (NIR LED) as radiation source, a PbSe photoresistor as infrared detector and a programmable interrupt controller (PIC) microcontroller as control unit. The detector system presents a thermoresistor and a thermoelectric cooling to control the detector temperature and keep the noise at low levels. The microcontroller incorporated total autonomy on the proposed photometer. As its components are inexpensive and of easy acquisition, the proposed NIR LED-photometer is an economical alternative for chemical analyses in small routine, research and/or teaching laboratories. By being portable and microcontrolled, it also allows carrying out field chemical analyses. The instrument was successfully applied on the screening analysis to verify adulteration in gasoline samples.
Changho Choi - One of the best experts on this subject based on the ideXlab platform.
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S-OpenSGX: A system-level platform for exploring SGX enclave-based computing
Computers & Security, 2017Co-Authors: Changho Choi, Nohyun Kwak, Jinsoo Jang, Daehee Jang, Kyungsoo Kwag, Brent Byunghoon KangAbstract:Abstract Intel recently introduced Software Guard Extensions (SGX) to enable applications to protect their selected code and data from privileged platform software. As it draws wider attention from the security research community, an open-source emulator for SGX (OpenSGX) has been developed to allow researchers to explore the SGX environment. To the best of our knowledge, OpenSGX is currently the only publicly available SGX emulation platform; however, its system-level support is largely limited owing to its user-mode emulation. In particular, experiments that require system functionalities or device emulation cannot be conducted with the current OpenSGX. To solve this problem, we propose System-OpenSGX (S-OpenSGX), which leverages QEMU's system emulation to provide researchers with full system-level support for exploring SGX enclave-based programming. In this paper, we show the design of S-OpenSGX, including system functionalities such as scheduling, multithreading, page table handling, and SGX paging. Non-trivial issues derived from the difference between user-mode and system emulation, and our approaches to addressing them are also described. Lastly, we utilize S-OpenSGX to experiment with a new mitigation method against the data leaking attack on enclave threads and an APIC (Advanced programmable interrupt controller) device modification to reduce SGX's mode switch overhead.
Sc Dsp - One of the best experts on this subject based on the ideXlab platform.
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Freescale Semiconductor Data Sheet
2013Co-Authors: Four Starcore, Sc DspAbstract:unified 512 Kbyte L2 cache configurable as M2 memory in 64 Kbyte increments, memory management unit (MMU), extended programmable interrupt controller (EPIC), two general-purpose 32-bit timers, debug and profiling support, low-power Wait, Stop, and power-down processing modes, and ECC/EDC support. Chip-level arbitration and switching system (CLASS) that provides full fabric non-blocking arbitration between the cores and other initiators and the M2 memory, shared M3 memory, DDR SRAM controllers, device configuration control and status registers, and other targets. 1056 Kbyte 128-bit wide M3 memory, 1024 Kbytes of which can be turned off to save power. 96 Kbyte boot ROM. Three input clocks (one global and two differential). Five PLLs (three global and two Serial RapidIO PLLs). Two DDR controllers with up to a 400 MHz clock (800 MHz data rate), 64/32 bit data bus, supporting up to a total 2 Gbyte in up to four banks (two per controller) and support for DDR2 and DDR3. • DMA controller with 32 unidirectional channels supporting 16 memory-to-memory channels with up to 1024 buffer descriptors per channel, and programmable priority, buffer, and multiplexing configuration. It is optimized for DDR SDRAM. Up to four independent TDM modules with programmable word size (2, 4, 8, or 16-bit), hardware-base A-law/μ-law conversion, up to 62.5 Mbps data rate for each TDM link, and with glueless interface to E1 or T1 framers that can interface with H-MVIP/H.110 devices, TSI, and codecs such as AC-97
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Freescale Semiconductor Data Sheet
2013Co-Authors: Four Starcore, Sc DspAbstract:unified 512 Kbyte L2 cache configurable as M2 memory in 64 Kbyte increments, memory management unit (MMU), extended programmable interrupt controller (EPIC), two general-purpose 32-bit timers, debug and profiling support, low-power Wait, Stop, and power-down processing modes, and ECC/EDC support. Chip-level arbitration and switching system (CLASS) that provides full fabric non-blocking arbitration between the cores and other initiators and the M2 memory, shared M3 memory, DDR SRAM controllers, device configuration control and status registers, MAPLE-B, and other targets. 1056 Kbyte 128-bit wide M3 memory, 1024 Kbytes of which can be turned off to save power. 96 Kbyte boot ROM. Three input clocks (one global and two differential). Five PLLs (three global and two Serial RapidIO PLLs). Multi-Accelerator Platform Engine for Baseband (MAPLE-B) with a programmable system interface, Turbo decoding, Viterbi decoding, and FFT/iFFT and DFT/iDFT processing. MAPLE-B can be disabled when not required to reduce overall power consumption. Two DDR controllers with up to a 400 MHz clock (800 MHz data rate), 64/32 bit data bus, supporting up to a total 2 Gbyte in up to four banks (two per controller) and support for DDR2 and DDR3. • DMA controller with 32 unidirectional channels supporting 16 memory-to-memory channels with up to 1024 buffer descriptors per channel, and programmable priority, buffer, and multiplexing configuration. It is optimized for DDR SDRAM. Up to four independent TDM modules with programmable word size (2, 4, 8, or 16-bit), hardware-base A-law/μ-law conversion, up to 62.5 Mbps data rate for each TDM link, and with glueless interface to E1 or T1 framers that can interface with H-MVIP/H.110 devices, TSI, and codecs such as AC-97
Sérgio Ricardo Bezerra Santos - One of the best experts on this subject based on the ideXlab platform.
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A portable, inexpensive and microcontrolled spectrophotometer based on white LED as light source and CD media as diffraction grid
Talanta, 2008Co-Authors: Germano Véras, Edvan Cirino Da Silva, Wellington Da Silva Lyra, Sófacles Figueredo Carreiro Soares, Thiago Brito Guerreiro, Sérgio Ricardo Bezerra SantosAbstract:Abstract A portable, microcontrolled and low-cost spectrophotometer (MLCS) is proposed. The instrument combines the use of a compact disc (CD) media as diffraction grid and white light-emitting diode (LED) as radiation source. Moreover, it employs a phototransistor with spectral sensitivity in visible region as phototransductor, as well as a programmable interrupt controller (PIC) microcontroller as control unit. The proposed instrument was successfully applied to determination of food colorants (tartrazine, sunset yellow, brilliant blue and allura red) in five synthetics samples and Fe 2+ in six samples of restorative oral solutions. For comparison purpose, two commercial spectrophotometers (HP and Micronal) were employed. The application of the t -paired test at the 95% confidence level revealed that there are not significant differences between the concentration values estimated by the three instruments. Furthermore, a good precision in the analyte concentrations was obtained by using MLCS. The overall relative standard deviation (R.S.D.) of each analyte was smaller than 1.0%. Therefore, the proposed instrument offers an economically viable alternative for spectrophotometric chemical analysis in small routine, research and/or teaching laboratories, because its components are inexpensive and of easy acquisition.