Hardware Trojan detection is a critical topic for maintaining the security of IC supply chain. Previous studies have reported some HT detection methods by reverse engineering manufactured chips, extracting design data, and comparing it with golden design data that is verified to be free of HT. However, there is a problem in terms of inspection time because time-consuming, high-resolution methods such as scanning electron microscope (SEM) must be used to accurately extract the structure of submicron order ICs. Typically, the inspector does not know where the HT is placed on the chip, and it takes an unrealistic amount of time to scan the entire chip with SEM to reconstruct the design data. In addition, SEM inspection involves destructive processes such as delayering. The inspector must identify chips suspected of HT insertion before inspection. In this paper, we propose an HT detection flow with a screening process that identifies suspected HT-inserted chips and the location of HT insertion prior to a high-resolution imaging process such as SEM. The screening process observes transistor layers by near-infrared (NIR) imaging from the backside of the IC and quickly and non-destructively detects additional logic cells laid out from the HT trigger circuit insertion. Although NIR is not suitable for observing microstructures such as the bottom wire layers due to its optical limitation, its resolution is sufficient to detect large structural changes such as groups of multiple logic cells. In the experiment, backside NIR observation was performed on a TEG chip fabricated with a 180 nm process. We show that logic cells of a certain size, such as FFs, can be resolved by NIR imaging.
SiC fibers with various C/Si atomic ratio have been prepared. These fibers were obtained by curing of polycarbosilane fibers with electron beam irradiation and pyrolysis. Microstructure, thermal stability, oxidation resistance, and creep resistance of these fibers were examined. Near-Stoichiometric SiC fiber(Si-1.05 C-0.02O), which was obtained under controlled fabrication conditions, exhibited excellent mechanical and thermal properties.
SiC‐based fibers with various chemical compositions were synthesized using an irradiation‐curing process. Polycarbosilane (PCS) fibers were cured by irradiation with an electron beam in a helium atmosphere. The cured PCS fibers were pyrolyzed at 1300°C under controlled hydrogen or argon atmospheres, and SiC fibers with C/Si of 0.84 to 1.56 were obtained. The fibers consisted of <1.0 wt% O, <0.2 wt% N, <0.1 wt% H, with the balance being Si and C. The mechanism of pyrolytic transformation of cured PCS to SiC‐based ceramics was investigated using TG/DTA analysis. Greater mass losses were observed during pyrolysis in a hydrogen atmosphere than in argon. This result suggests that the hydrogen atmosphere suppresses H 2 evolution and helps to remove excess carbon as CH 4 during pyrolysis. The microstructure and mechanical properties of the resulting SiC‐based fibers were found to be very dependent on their C/Si chemical compositions.
A 3D graphics engine consists of a programmable floating-point geometry engine and a rasterization engine to adapt to various memory-based set associative cache mechanism. The IC achieves 4.7M vertex/s and 600M texel /s systems, the rasterization engine has a coordinate I and dissipates 109.5mW. A 0.18 /spl mu/m 5M CMOS process is used to implement the 25.4mm/sup 2/ IC operating at 1.2V.
In Japan, annuities are not currently very popular as a means to finance retirement, since many people rely on government social security benefits in old age. When annuities are sold, they tend not to be life payouts but rather term-certain products. In this sense, the annuity puzzle also applies to Japan. We discuss possible reasons for the unpopularity of annuity products, including costs and inequitable taxation that hinders people from buying them.
The RAM encryption encrypts the data on memory to prevent data leakage from an adversary to eavesdrop the memory space of the target program. The well-known implementation is Intel SGX, whose RAM encryption mechanism is definitely hardware dependent. In contrast, Watanabe et al. proposed a fully software-based RAM encryption scheme (SBRES). In this paper, we developed the tools for embedding the SBRES in C source codes for its practical application. We applied the tools to the source codes of some cryptographic implementations in Mbed TLS and confirmed that the tools successfully embedded the SBRES functionality in the cryptographic implementations.
