Hong D.,Attached Institute of ETRI |
Koo B.,Attached Institute of ETRI |
Sasaki Y.,NTT Corporation |
Sasaki Y.,University of Electro - Communications
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2010
In this paper, we improve previous preimage attacks on hash function HAS-160, which is standardized in Korea. We show that the last 68 steps out of 80 steps of HAS-160 can be attacked, while a previous attack works for only intermediate 52 steps. We also show that the first 67 steps of HAS-160 can be attacked. These attacks are based on the meet-in-the-middle attack, which is also used in the previous attack. Recently, various techniques of preimage attacks have been proposed on other hash functions. We show that these techniques can also be applied to HAS-160 and the number of attacked steps can be improved. For the attack on 68 steps, we first generate pseudo-preimages with a complexity of 2150.7, and then convert them to a preimage with a complexity of 2156.3. This attack uses a memory of 212 ×7 words. To the best of our knowledge, attacking 68 steps is the best of all attacks on HAS-160 hash function. © 2010 Springer-Verlag.
Yoshimoto N.,NTT Corporation |
Kani J.-I.,NTT Corporation |
Kim S.-Y.,NTT Corporation |
Iiyama N.,NTT Corporation |
Terada J.,NTT Corporation
IEEE Communications Magazine | Year: 2013
Motivated by recent progress in next-generation PON2, or NG-PON2, standardization, this article reviews digital signal processing technologies to further enhance NG-PON2 systems by realizing flexible and cost-effective optical access network deployments. First, flexible speed upgrades by DSP-enabled advanced modulation and multiplexing approaches are described, followed by a consideration of cost-performance trade-offs. Next, reach extension using DSPbased digital coherent reception and impairment compensation is overviewed. Finally, as a future goal, access network virtualization with reconfigurable optical line terminals and optical network units is discussed. © 1979-2012 IEEE.
Miyamoto Y.,NTT Corporation |
Suzuki S.,NTT Corporation
IEEE Communications Magazine | Year: 2010
Digital signal processing technologies are key enablers for realizing high-capacity Optical Transport Network based on over 100 Gb/s and above channels. Novel no-guard-interval OFDM with frequency domain equalization is proposed and shown to offer excellent long-haul transport with capacity well above 10 Tb/s. © 2010 IEEE.
N.T.T. Inc. | Date: 2013-04-11
N.T.T. Inc. | Date: 2013-04-12
NTT Corporation | Date: 2013-08-31
Electronic cigarette liquid (e-liquid) comprised of flavorings in liquid form used to refill electronic cigarette cartridges.
N.T.T. Inc. | Date: 2012-05-15
PubMed | Osaka University, Ehime University, Kyoto University and NTT Corporation.
Type: | Journal: Studies in health technology and informatics | Year: 2016
Issues related to ensuring patient privacy and data ownership in clinical repositories prevent the growth of translational research. Previous studies have used an aggregator agent to obscure clinical repositories from the data user, and to ensure the privacy of output using statistical disclosure control. However, there remain several issues that must be considered. One such issue is that a data breach may occur when multiple nodes conspire. Another is that the agent may eavesdrop on or leak a users queries and their results. We have implemented a secure computing method so that the data used by each party can be kept confidential even if all of the other parties conspire to crack the data. We deployed our implementation at three geographically distributed nodes connected to a high-speed layer two network. The performance of our method, with respect to processing times, suggests suitability for practical use.
NTT Corporation | Date: 2013-06-13
PubMed | NTT Corporation.
Type: Journal Article | Journal: Analytical sciences : the international journal of the Japan Society for Analytical Chemistry | Year: 2017
The Raman spectroscopy of pharmaceutical cocrystals based on caffeine and oxalic acid in nanosized pores of mesoporous silica has been demonstrated at various molar amounts. The Raman peak shifts of caffeine molecules express the existence of pharmaceutical cocrystals in mesoporous silica. The molar amount dependence of the peak shifts describes that caffeine and oxalic acid cocrystallized on the surface of the nanosized pores and piled up layer by layer. This is the first report that shows the Raman spectroscopy is a powerful tool to observe the synthesis of pharmaceutical cocrystals incorporated in the nanosized pores of mesoporous silica. The results indicate a way to control the size of cocrystals on a nanometer scale, which will provide higher bioavailability of pharmaceuticals.