• Title/Summary/Keyword: 51% attack

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Hardware Design of 352-bit Cipher Algorithm (352-비트 암호 알고리즘의 하드웨어 설계)

  • Park, Young Ho
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.5 no.1
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    • pp.51-61
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    • 2009
  • Conventional DES has been not only shown to have a vulnerable drawback to attack method called 'Meet in the Middle', but also to be hard to use that it is because software implementation has a number of problem in real time processing. This paper describes the design and implementation of the expanded DES algorithm using VHDL for resolving the above problems. The main reason for hardware design of an encryption algorithm is to ensure a security against cryptographic attack because there is no physical protection for the algorithm written in software. Total key length of 352 bits is used for the proposed DES. The result of simulation shows that the inputted plaintext in cryptosystem are equal to the outputted that in decryptosystem.

A Reliable 2-mode Authentication Framework for Wireless Sensor Network (무선 센서네트워크를 위한 신뢰성 있는 2-모드 인증 프레임워크)

  • Huyen, Nguyen Thi Thanh;Huh, Eui-Nam
    • Journal of Internet Computing and Services
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    • v.10 no.3
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    • pp.51-60
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    • 2009
  • This paper proposes a reliable 2-mode authentication framework for probabilistic key pre-distribution in Wireless Sensor Network (WSN) that guarantees the safe defense against different kinds of attacks: Hello flood attacks, Wormhole attacks, Sinkhole attack, location deployment attacks, and Man in the middle attack. The mechanism storing the trust neighbor IDs reduces the dependence on the cluster head and as the result; it saves the power energy for the authentication process as well as provides peer-to-peer communication.

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A Study of Prescription Analysis on Patients with Ischemic Heart Disease and Evaluation of Antihypertensive Drug Use in General Hospital (종합병원 허혈성 심장질환 환자의 항고혈압약제 사용 현황 및 평가)

  • Moon, Kyoung-Sil;Song, Hyun-Ju;Sohn, Uy-Dong
    • YAKHAK HOEJI
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    • v.51 no.5
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    • pp.336-342
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    • 2007
  • Treatment of hypertension is important in reducing death and attack rates by Ischemic heart disease (IHD). The purposes of this study are to investigate recent prescriptions for patients with IHD and to evaluate antihypertensive drug use. On the basis of the guidelines proposed by Seventh Report of the Joint National Committee on prevention, detection, evaluation, and treatment of high blood pressure, we analyzed prescriptions of antihypertensive drugs for patients with IHD. It is necessary to set up new guideline for appropriate treatment to lower death and attack rates for patients with IHD.

Performance Improvement of Power Attacks with Truncated Differential Cryptanalysis (부정차분을 이용한 전력분석 공격의 효율 향상*)

  • Kang, Tae-Sun;Kim, Hee-Seok;Kim, Tae-Hyun;Kim, Jong-Sung;Hong, Seok-Hie
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.19 no.1
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    • pp.43-51
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    • 2009
  • In 1998, Kocher et al. introduced Differential Power Attack on block ciphers. This attack allows to extract secret key used in cryptographic primitives even if these are executed inside tamper-resistant devices such as smart card. At FSE 2003 and 2004, Akkar and Goubin presented several masking methods, randomizing the first few and last few($3{\sim}4$) rounds of the cipher with independent random masks at each round and thereby disabling power attacks on subsequent inner rounds, to protect iterated block ciphers such as DES against Differential Power Attack. Since then, Handschuh and Preneel have shown how to attack Akkar's masking method using Differential Cryptanalysis. This paper presents how to combine Truncated Differential Cryptanalysis and Power Attack to extract the secret key from intermediate unmasked values and shows how much more efficient our attacks are implemented than the Handschuh-Preneel method in term of reducing the number of required plaintexts, even if some errors of Hamming weights occur when they are measured.

A Detect and Defense Mechanism of Stateful DRDoS Attacks (상태기반 DRDoS 공격에 대한 탐지 및 방어기법)

  • Kim, Minjun;Seo, Kyungryong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.5
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    • pp.127-134
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    • 2014
  • In DRDoS(Distributed Reflective Denial of Service) attacks, the victim is bombarded by packets from legitimate reflector unlike DDoS(Distributed Denial of Service) attacks through zombie, which is more dangerous than DDoS attack because it is in stronger disguise. Therefore, the method of filtering packet method on router are useless. Moreover SCTP(Stream Control Transmission Protocol) multi-homing feature, such as with an improved transmission protocol allows detecting attacks is more difficult and the effect of the attack can be maximized. In this paper we propose a DRDoS detection mechanism based on DRDoS utilizing attention to the characteristics of stateful protocols. The proposed scheme is backed by stateful firewall, and detect DRDoS attacks through a rules table and perform a defense treatment against DRDoS attack. Rules table with a simple structure is possible to easily adapt for any kind of stateful protocol can used by DRDoS attack. The experimental result confirm that our proposed scheme well detect DRDoS attacks using SCTP, the next-generation transmission protocol which not known by victim, and reduce the attacking packets rapidly.

An Acute Postoperative Intractable Hyperventilation after an Endoscopic Third Ventriculostomy

  • Lee, Hae-Mi;Shin, Kyung-Bae;Kim, Seong-Ho;Jee, Dae-Lim
    • Journal of Korean Neurosurgical Society
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    • v.51 no.3
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    • pp.173-176
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    • 2012
  • This report describes a rare case of postoperative hyperventilation attack after an endoscopic third ventriculostomy in a 46-year-old woman. About 60 min after the termination of the operation, an intractable hyperventilation started with respiratory rate of 65 breaths/min and $EtCO_2$, 16.3 mm Hg. Sedation with benzodiazepine, thiopental sodium, fentanyl, and propofol/remifentanil infusion was tried under a rebreathing mask at a 4 L/min of oxygen. With aggressive sedative challenges, ventilation pattern was gradually returned to normal during the 22 hrs of time after the surgery. A central neurogenic hyperventilation was suspected due to the stimulating central respiratory center by cold acidic irrigation solution during the neuroendoscopic procedure.

Numerical study on fluid flow by hydrodynamic loads in reactor internals

  • Kim, Da-Hye;Chang, Yoon-Suk;Jhung, Myung-Jo
    • Structural Engineering and Mechanics
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    • v.51 no.6
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    • pp.1005-1016
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    • 2014
  • Roles of reactor internals are to support nuclear fuel, provide insertion and withdrawal channels of nuclear fuel control rods, and carry out core cooling. In case of functional loss of the reactor internals, it may lead to severe accidents caused by damage of nuclear fuel assembly and deterioration of reactor vessel due to attack of fallen out parts. The present study is to examine fluid flows in reactor internals subjected to hydrodynamic loads. In this context, an integrated model was developed and applied to two kinds of numerical analyses; one is to analyze periodic loading effect caused by pump pulsation and the other is to analyze random loading effect employing different turbulent models. Acoustic pressure distributions and flow velocity as well as pressure and temperature fields were calculated and compared to establish appropriate analysis techniques.

Delayed death after chlorfenapyr poisoning (클로르페나피르 중독 후 지연성 사망)

  • Lee, Jang Young
    • Journal of The Korean Society of Clinical Toxicology
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    • v.19 no.1
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    • pp.51-54
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    • 2021
  • Chlorfenapyr is a widely used insecticide, that is very lethal if ingested. It exhibits delayed toxicity in which there are few symptoms at first which suddenly worsen after a few days. A 66-year-old female patient ingested about 90 mL of chlorfenapyr liquid hydrating agent (Chlofenapyr 10%) and showed stable vital signs with no specific symptoms and findings other than a mild fever, vomiting, and nausea. From the 3rd day of ingestion, creatine kinase was high, and rhabdomyolysis was suspected. From the 4th day of ingestion, pancreatic enzymes began to gradually increase. A diffusion-weighted image showed a multifocal high signal intensity in the white matter and corpus callosum area. On the 8th day after ingestion, she suffered a high fever and a heart attack and died. Thus, if a patient is suspected of taking chlorfenapyr, he/she needs active treatment and monitoring even if he/she does not exhibit any symptoms.

The Real-Time Detection of the Malicious JavaScript (실시간으로 악성 스크립트를 탐지하는 기술)

  • Choo, Hyun-Lock;Jung, Jong-Hun;Kim, Hwan-Kuk
    • Journal of Internet Computing and Services
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    • v.16 no.4
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    • pp.51-59
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    • 2015
  • JavaScript is a popular technique for activating static HTML. JavaScript has drawn more attention following the introduction of HTML5 Standard. In proportion to JavaScript's growing importance, attacks (ex. DDos, Information leak using its function) become more dangerous. Since these attacks do not create a trail, whether the JavaScript code is malicious or not must be decided. The real attack action is completed while the browser runs the JavaScript code. For these reasons, there is a need for a real-time classification and determination technique for malicious JavaScript. This paper proposes the Analysis Engine for detecting malicious JavaScript by adopting the requirements above. The analysis engine performs static analysis using signature-based detection and dynamic analysis using behavior-based detection. Static analysis can detect malicious JavaScript code, whereas dynamic analysis can detect the action of the JavaScript code.

Analysis on Changes in Strength, Chloride Diffusion, and Passed Charges in Normal Concrete Considering Ages and Mix Proportions (재령 및 배합특성을 고려한 보통 콘크리트의 강도, 염화물 확산계수, 통과전하량 변화 분석)

  • Lee, Hack-Soo;Kwon, Seung-Jun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.5 no.1
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    • pp.1-7
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    • 2017
  • Concrete behavior in early-age is changing due to hydration reaction with time, and a resistance to chloride attack and strength development are different characterized. In the present work, changing strength and resistance to chloride attack are evaluated with ages from 28 days to 6 months. For the purpose, strength, diffusion coefficient, and passed charge are evaluated for normal concrete with 3 different mix proportions considering 28-day and 6-month curing conditions. With increasing concrete age, the changing ratio of strength falls on the level of 135.3~138.3%, while diffusion coefficient and passed charge shows 41.8%~51.1% and 53.6%~70.0%, respectively. The results of chloride diffusion coefficient and passed charge show relatively similar changing ratios since they are much dependent on the chloride migration velocity in electrical field. The changing ratios in chloride behaviors are evaluated to be much larger than those in compressive strength since the ion transport mechanism is proportional to not porosity but square of porosity.