• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2001.11a
• /
• pp.132-138
• /
• 2001

본 논문에서는 타원곡선 스칼라 곱셈에 대하여 새로운 형태의 hardware fault cryptanalysis를 적용해 보고, 이에 대한 대응방법으로서 비밀키 blinding방법을 제안하고 있다. 또한 비밀키 blinding 방법을 사용함으로써 늘어나는 연산량을 기존의 대응 방법과 비교하고, 이러한 비밀키 blinding방법이 사용될 수 있는 범위에 대해 다루고 있다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 2006.06a
• /
• pp.164-168
• /
• 2006

전력 공격은 암호화 연산 과정 중 발생하는 소비 전력의 파형을 측정하여 비밀 정보를 알아내는 공격 방식이다. 이러한 전력 공격에 대한 취약성을 막기 위하여 message blinding, exponent blinding과 같은 기법들이 적용되어 왔다. 본 고에서는 $ECC^{[1]}$암호화 연산 과정에서, r이 임의의 정수일 때, dP=(d-r)P+rP인 관계를 이용하는 exponent blinding기법$^{[2]}$에 대하여 언급하고, 위 기법을 전력 공격의 대응책으로 적용 시 적절히 구현되지 않으면 power attack에 대하여 매우 취약하다는 것을 보인다.

• Journal of Acupuncture Research
• /
• v.24 no.1
• /
• pp.127-135
• /
• 2007

Objectives: To evaluate the methodological quality of Korean Acupuncture Clinical trials Methods : Two independent researchers reviewed 12 protocols of Acupuncture clinical trials which were conducted in Korea 2006. Also, Survey Principal Investigator of those was conducted. We compare the results of protocol review with investigator reponses of actual practice. Quality assessment consisted of 5 items including random sequence generation, randomization method, allocation concealment, subject blinding, assessor blinding. Results : Randomization was performed using the proper procedure to insure that treatment assignment is unbiased and concealed from subjects in all clinical trials, According to protocols, 6(50%) of 12 clinical trials used computer-generated random numbers, 6(50%) remaining trials didn't describe the randomization method. Also all trials used appropriate randomization methods on the basis of the survey results: 8 trials used computer-generated random number, 2 used random table. Of 7 protocols in which allocation concealment was stated, 5(71%) reported appropriate method (Calling a central office or statisticians, Sealed opaque envelopes). However according to survey, 5(42%) of 12 trials used inappropriate allocation concealment (Keeping a master randomization list and referring to when subject entered the trial). In addition, the result of protocol review and survey response was not coincident in 5(42%) trials. Subject blinding was conducted in all except 1 clinical trials. Although 11(92%) of 12 trials were conducted using assessor blinding in actual practice, only 7(58%) reported that in protocol. Conclusion : Although randomization and blinding were conducted adequately, allocation concealment was used inadequately, Not only appropriate allocation concealment, but also every quality assessment item including randomization, blinding should be stated in more detail in protocol.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1998.12a
• /
• pp.231-242
• /
• 1998

전자 상거래에 대한 다양한 프로토타입(prototype)이 구현되고 있고, 확대 적용의 현실성이 증대되고 있는 작금의 상황을 반영하여 관련 연구가 활발해지고 있으며, 그 중에서 보다 안전하고 효율적인 전자지불방식에 대한 현실적 요구가 증대하고 있다 전자지불방식의 하나인 전자화폐는 실물 화폐와 유사한 성질들을 만족해야 하며, 이러한 성질들 중에서 필수적인 익명성을 얻기 위한 방법으로는 D. Chaum이 제안한 Blind Signature가 대표적이다. 본 논문에서는 기존의 암호시스템의 문제점을 극복할 수 있는 시스템으로써 주목받고 있는 타원곡선 암호시스템 상에서 익명성을 제공하는 Blinding ECDSA를 제안한다.

• Korean Journal of Acupuncture
• /
• v.25 no.4
• /
• pp.175-185
• /
• 2008

Objective : Acupuncture (from the Latin acus, "needle," and pungere, "to prick") is a technique of inserting and manipulating fine needles at specific points on the body. As a placebo acupuncture needle device was developed based on the visual impact of needling, it has been raised that it is useful only when acupuncture points and needling are visible to subjects. To examine the visual factor of the placebo acupuncture, the present study was aimed to compare the blinding index of the verum and placebo acupuncture between masked and unmasked situation. Methods : Thirty-six patients were randomly alloted to be stimulated with a verum or placebo acupuncture in a cross-over design. They were asked to guess a right answer whether they were stimulated with the verum or placebo acupuncture at LI4 in an unmasked or masked situation. The penetrating, pain, and deqi sensations were also measured after the stimulation using modified visual analogue scale. Results : The correct answer rate of the placebo acupuncture was 22.2% and 16.7% in an unmasked and masked situation, respectively (P>0.767). The blinding index of the placebo acupuncture was -0.56 (95%CI -0.84 to -0.27) and -0.67 (95%CI -0.91 to -0.42) in an unmasked and masked situation, respectively. The penetrating and deqi sensation of the verum acupuncture were significantly higher than those of the placebo acupuncture in both unmasked and masked situation. The pain sensation of the verum acupuncture was significantly higher than that of the placebo acupuncture in masked situation, but not in unmasked situation. Conclusion : Blinding of the placebo acupuncture was successful both in the unmasked and masked situation. These finding indicate that visual factor might not play a critical role in blinding of the placebo needle. We suggest that placebo needle would be also useful in a functional magnetic resonance imaging scan even when the subject could not see the placebo needle.

• ETRI Journal
• /
• v.32 no.1
• /
• pp.102-111
• /
• 2010

Recently power attacks on RSA cryptosystems have been widely investigated, and various countermeasures have been proposed. One of the most efficient and secure countermeasures is the message blinding method, which includes the RSA derivative of the binary-with-random-initial-point algorithm on elliptical curve cryptosystems. It is known to be secure against first-order differential power analysis (DPA); however, it is susceptible to second-order DPA. Although second-order DPA gives some solutions for defeating message blinding methods, this kind of attack still has the practical difficulty of how to find the points of interest, that is, the exact moments when intermediate values are being manipulated. In this paper, we propose a practical second-order correlation power analysis (SOCPA). Our attack can easily find points of interest in a power trace and find the private key with a small number of power traces. We also propose an efficient countermeasure which is secure against the proposed SOCPA as well as existing power attacks.

• Journal of Acupuncture Research
• /
• v.22 no.4
• /
• pp.189-195
• /
• 2005

Objectives : This study was to evaluate the effectiveness of Bee Venom acupuncture therapy on sprain of C-spine by randomized controlled double blinding method. Methods : A randomized double blinding study of bee venom acupuncture therapy was conducted on sprain of C-spine. We divided sprain of C-spine patient into 2 groups: one group with both acupuncture and saline acupuncture therapy, and another group with both acupuncture and bee venom acupuncture therapy. To estimate the efficacy of treatment that applied for two groups, we used visual analog scale(VAS) and neck disability index(NDI). We compared the VAS and NDI score of two groups statistically. Results : STZ induced increase of serum creatinine, BUN and albumin secretion were lowered by AD-1 treatment.

• ETRI Journal
• /
• v.32 no.3
• /
• pp.362-369
• /
• 2010

While the elliptic curve cryptosystem (ECC) is getting more popular in securing numerous systems, implementations without consideration for side-channel attacks are susceptible to critical information leakage. This paper proposes new power attack countermeasures for ECC over Koblitz curves. Based on some special properties of Koblitz curves, the proposed methods randomize the involved elliptic curve points in a highly regular manner so the resulting scalar multiplication algorithms can defeat the simple power analysis attack and the differential power analysis attack simultaneously. Compared with the previous countermeasures, the new methods are also noticeable in terms of computational cost.

• Journal of Acupuncture Research
• /
• v.22 no.4
• /
• pp.113-120
• /
• 2005

objectives : This study was to evaluate the effectiveness of Bee Venom acupuncture therapy for sprain of L -spine. Methods : A randomized double blinding study of bee venom acupuncture therapy was conducted on sprain of L-spine. We divided sprain of L-spine patient into 2 groups: one group with both acupuncture and saline acupuncture therapy, and another group with both acupuncture and bee venom acupuncture therapy. To estimate the efficacy of treatment that applied for two groups, we used visual analog scale(VAS) and oswestry disability index(ODI). We compared the VAS and ODI score of two groups statistically. Results : 1. As a result of evaluation by using visual analog scale(VAS) and oswestry disability index(ODI), treatment score after 5 days was marked more higher than score before treatment and treatment score after 10 days treatment was more higher than treatment score after 5 days on each groups. 2. After 10 days treatment, acupuncture and bee venom acupuncture therapy group had significant result on visual analog scale(VAS) and oswestry disability index(ODI) compared with acupuncture and saline acupuncture therapy group. Conclusion : Bee Venom acupuncture therapy can be used with acupuncture therapy for highly effective treatment for sprain of L-spine.

• Applied Chemistry for Engineering
• /
• v.18 no.1
• /
• pp.29-35
• /
• 2007

Recently, due to narrow margin on design factor of flue gas desulfurization (FGD) systems or aging of systems, some problems such as decrease of $SO_2$ removal efficiency and difficulty on coping with unstable state are arising on FGD systems. On this study, to cope with these problems several methods such as adjustment of reagent pH, inlet $SO_2$ concentration, variation of units of operation pump, installation of liquid distribution ring (LDR) were attempted to increase the $SO_2$ removal using spray type simulated FGD system. Also, sulfite and Al/Fx ion effects on limestone blinding were experimented. When three absorber recirculation pumps were operated, $SO_2$ removal was increased by 12% in comparison with that of two pumps operation. $SO_2$ removal was increased by 2~7% after installation of LDR. Dissolved oxygen increased up to 0.5 ppm and limestone binding effect was alleviated after injection of dibasic acid (DBA) with the concentration of 500 and 1,000 ppm. When $Al^{3+}$ and $F^-$ ions were coexisting, the dissolution rate of limestone was decreased by 20%.