• Journal of Digital Convergence
• /
• v.13 no.10
• /
• pp.343-351
• /
• 2015

With the diverse services of the current M2M environment being expanded to the organizations, the corporations, and the daily lives, the possibility of the occurrence of the vulnerabilities of the security of the related technologies have become an issue. In order to solve such a problem of the vulnerability of the security, this thesis proposes the technique for applying the cryptography algorithm for the protection of the device key of the M2M environment. The proposed technique was based on the elliptic curve cryptography Through the key exchange and the signature exchange in the beginning, the security session was created. And the white box cipher was applied to the encryption that creates the white box table using the security session key. Application results cipher algorithm, Elliptic Curve Cryptography provides a lightweight mutual authentication, a session key for protecting the communication session and a conventional white-box cipher algorithm and was guaranteed the session key used to encrypt protected in different ways. The proposed protocol has secure advantages against Data modulation and exposure, MITM(Man-in-the-middle attack), Data forgery and Manipulation attack.

• Journal of KIISE:Computing Practices and Letters
• /
• v.8 no.1
• /
• pp.88-95
• /
• 2002

In recent years, the security of hardware and software systems is one of the most essential factor of our safe network community. As elliptic Curve Cryptosystems proposed by N. Koblitz and V. Miller independently in 1985, require fewer bits for the same security as the existing cryptosystems, for example RSA, there is a net reduction in cost size, and time. In this thesis, we propose an efficient hardware architecture of underlying field arithmetic processor for Elliptic Curve Cryptosystems, and a very useful method for implementing the architecture, especially multiplicative inverse operator over GF$GF (2^m)$ onto FPGA and futhermore VLSI, where the method is based on optimized unit operation components. We optimize the arithmetic processor for speed so that it has a resonable number of gates to implement. The proposed architecture could be applied to any finite field $F_{2m}$. According to the simulation result, though the number of gates are increased by a factor of 8.8, the multiplication speed We optimize the arithmetic processor for speed so that it has a resonable number of gates to implement. The proposed architecture could be applied to any finite field $F_{2m}$. According to the simulation result, though the number of gates are increased by a factor of 8.8, the multiplication speed and inversion speed has been improved 150 times, 480 times respectively compared with the thesis presented by Sarwono Sutikno et al. [7]. The designed underlying arithmetic processor can be also applied for implementing other crypto-processor and various finite field applications.

• Korea journal of population studies
• /
• v.29 no.1
• /
• pp.133-156
• /
• 2006

This paper tries to explore the overall profile of Korean female labor force over the period of 1960-2000. A particular emphasis is put on portraying major over-time characteristics of female labor force, following five different political regimes--that of Park, J.H.(1960 and 1970s), of Chon D.H. (early and late 1980s), of Roh T.W. (late 1980-early 1990s), of Kim,Y.S. (early 1990-1ate 1990s), and of Kim. D. J. (late 1990-early 2000s), respectively. Discussions have centered around: 1) utilization of young single girls from rural areas during the early industrialization process of 1960-1985; 2) the beginning of married women's entry into labor market and issues of the socalled &M-curve& thesis in Korean experiences since 1990s; 3) the emergence and enlargement of non-regular workers; and 4) the launching of labor related legal measures such as the Equal Employment Act of 1988 and its successive revisions, the Maternity Leave Acts, the On-the-Job Chi1dcare Centers, and the prohibition of sexual harassments on the job setting, and so on. All in all, although it is undeniable that the Korean female labor force has experienced much progress over the period of time in terms of &equality and protection& issues, overall industrial reality we are facing with has not been so prosperous in the sense that most women workers have become the victims of industrial polarization, as time goes by.

• Journal of radiological science and technology
• /
• v.10 no.1
• /
• pp.49-53
• /
• 1987

This thesis compared and analyzed the characteristics, centered on a characteristic curve, about X-ray computerized tomographic film generally used in Korea recently. The results were as follows: 1. Maximum gradient (gamma) was film A-2.19, film B-2.00, film C-1.92. 2. Latitude was confined within the limits of density 0.6-2.0 in all. 3. When we changed window center from 0 to 40, the difference of density, which was in 1.0, was film A-0.12, film B-0.16, fil m C-0.14. 4. When we changed window width from 0 to 500, the difference of density, which was in 1.0, was film A-0.06, film B-0.08, film C-0.05. 5. In the case of window width 50 and window center 20, latitude was 0.5-2.0, 0.5-2.2, 0.5-1.9 and gamma value was 1.74, 1.82, 1.72 respectively, 6. In the case of window width 80 and window center 30, latitude was 0.6-2.2, 0.6-2.3, 0.8-2.2 and gamma value was 2.0, 2.13, 1.95 respectively.

• The Journal of Korean Academy of Prosthodontics
• /
• v.37 no.6
• /
• pp.741-755
• /
• 1999

As a material of metal-ceramic prosthesis, nickel as a form of Ni-Cr alloy has been used for many dental prostheses in many cases. However, several problems in use of the alloy have been revealed (ex : tissue stimulation, skin allergy, hypersensitivity, cytotoxicity and carcinogenecity). Little is known about nickel with respect to the relationship between Ni-prosthesis and gaining of Ni-resistance in oral microorganisms. The present study was undertaken to check wheather use of Ni-prosthesis leads to occurrence of Ni-resistant microorganisms. So this study may suggest the possible relationships between the oral microorganisms and nickel-resistance in oral environment. Bacteria were isolated from the gingival crevicular fluid on the pateints wearing Ni-Cr prosthesis. The isolated bacteria were tested for their Ni-resistance in nickel containing media at different concentration from 3mM to 110mM. E. coli HB101 was used as control. The Ni-resistant bacteria were isolated and biochemically identified. The Ni-resistant bacteria were tested several bio-chemical, molecular-biological tests. Performed tests were ; measuring the growth curve, antibiotic test, growth ability test in liquid media, isolation of the chromosome and plasmid, digestion of DNA by restriction enzyme, electrophoresis of chromosome and plasmid DNA, identification of Ni-resistant genes by the DNA hybridization. The results were as follows: 1) The bacteria isolated from gingival crevicular fluid on the patients wearing Ni-Cr alloy pros-thesis showed nickel-resistance. 2) The isolated microorganisms grew at nickel containing media of high concentrations (60mM-110mM). 3) Based on the biochemical tests, the isolated microorganisms were identified as Enterococcus faecalis(13 cases), Klebsiella pneumoniae(1 case) and Enterobacter gergeviae(1 case). 4) Enterococcus faecalis expressed not only nickel resistance but also the multi-drug resistance to several antibiotics ; chloramphenicol, kanamicin, streptomycin, lincomycin, clindamycin. However, all strain showed the sensitivity against the tetracycline. 5) DNA hybridization result suggest that there is no homology between the previousely known gene of nickel resistance in Klebsiella pneumoniae and chromosomal DNA of Enterococcus faecalis.