• 제목/요약/키워드: 패딩 알고리즘

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Design of a Padding Algorithm Using the Pad Character Length (패딩 문자열 길이 정보를 이용한 패딩 알고리즘 설계)

  • Jang, Seung-Ju
    • Journal of Korea Multimedia Society
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    • v.9 no.10
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    • pp.1371-1379
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    • 2006
  • This paper suggests the padding algorithm using padding character length to concatenate more than one string without side-effect. Most existing padding algorithms padding null character in the empty location could not discriminate the real string from the padded character. To overcome this problem, in this paper, the padded character contains pad character length information. This mechanism is working better than NULL or '00' padding cases. The suggested padding algorithm could be effective for data encryption and decryption algorithms.

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Analysis of Padding Oracle Attack Possibility about Application Environment; SRTP, MIKEY, CMS, IPSec, TLS, IPTV (SRTP, MIKEY, CMS, IPSec, TLS, IPTV에 대한 패딩 오라클 공격 가능성 분석)

  • Hwang, Seongjin;Park, Myungseo;Moon, Dukjae;Kang, HyungChul;Kim, Jongsung;Lee, Changhoon
    • KIPS Transactions on Computer and Communication Systems
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    • v.4 no.2
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    • pp.73-80
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    • 2015
  • In the various application environments on the internet, we use verified cipher algorithm to protect personal information. Even so, if an application method isn't proper, the information you want to keep can be intercepted. One of the representative examples of it is a PADDING ORACLE ATTACK. This thesis studied about STRP, MIKEY, CMS, IPSec, TLS, IPTV, an application environment which apply CBC operational mode based on block cipher and CBC padding method, and about whether we can attack against the Padding Oracle Attack as well as the vulnerable points.

Safety Analysis of Various Padding Techniques on Padding Oracle Attack (패딩 오라클 공격에 따른 다양한 패딩방법의 안전성 분석)

  • Kim, Kimoon;Park, Myungseo;Kim, Jongsung;Lee, Changhoon;Moon, Dukjae;Hong, Seokhee
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.25 no.2
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    • pp.271-278
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    • 2015
  • We use various types of cryptographic algorithms for the protection of personal and sensitive informations in the application environments, such as an internet banking and an electronic commerce. However, recent researches were introduced that if we implement modes of operation, padding method and other cryptographic implementations in a wrong way, then the critical information can be leaked even though the underlying cryptographic algorithms are secure. Among these attacking techniques, the padding oracle attack is representative. In this paper, we analyze the possibility of padding oracle attacks of 12 kinds of padding techniques that can be applied to the CBC operation mode of a block cipher. As a result, we discovered that 3 kinds were safe padding techniques and 9 kinds were unsafe padding techniques. We propose 5 considerations when designing a safe padding techniques to have a resistance to the padding oracle attack through the analysis of three kinds of safe padding techniques.

Frame Distribution Methods for Link Aggregation between 10GbE Switches (10GbE 스위치간 링크 집합을 위한 프레임 분배방식)

  • 이호영;이숭희;김연수;조현성
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.04d
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    • pp.25-27
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    • 2003
  • 본 논문은 10GbE로의 망 전개에 따라 구현될 l0Gb 스위치에 필요한 계층2 부가서비스들 중에서 여러개의 물리적인 링크를 하나의 논리적인 링크로 집합하여 대역폭의 증가를 가져오는 링크 집합(Link Aggregation) 기술에 필요한 프레임 분배방식에 대한 것이다. 링크 집합 기술은 분배 알고리즘의 설계에 따라 스위치에서 성능의 차이를 가져오므로 링크 집합의 장정을 살리려면 종은 성능을 가지는 분배 알고리즘이 필요하다. 우선 링크 집합의 간단한 구현 방법을 살펴보고 기존에 제시된 스위치와 스위치 사이에서의 프레임 분배방식인 정적/동적 프레임 분배 방식과 우리가 새로이 제안한 패딩을 이용한 분배방식을 비교한 후, 정적/동적 프레임 분배 방식과 패딩을 이용한 분배방식을 컴퓨터 시뮬레이션을 통해 성능을 비교하였다.

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Padding Oracle Attack on Block Cipher with CBC|CBC-Double Mode of Operation using the BOZ-PAD (BOZ-PAD 방법을 사용하는 블록암호 기반 CBC|CBC 이중 모드에 대한 패딩 오라클 공격)

  • Hwang, Seongjin;Lee, Changhoon
    • The Journal of Society for e-Business Studies
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    • v.20 no.1
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    • pp.89-97
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    • 2015
  • In the various application environments on the internet, we use verified cipher algorithm to protect personal information of electronic commerce or application environments. Even so, if an application method isn't proper, the information you want to keep can be intercepted. This thesis studied about result of Padding Oracle Attack, an application environment which apply CBC|CBC operational mode based on block cipher and BOZ padding method.

Frame Distribution Methods for Link Aggregation between 10GbE Switches (10GbE 스위치간 링크 집합을 위한 프레임 분배방식)

  • 이호영;이숭희;이종협
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.12A
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    • pp.945-950
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    • 2003
  • The link aggregation between 10GbE switches requires an advanced frame distribution method to be properly and efficiently applied. The fixed or dynamic frame distribution methods, formerly proposed, cannot fully utilize the aggregated links, where the receiving terminal only attaches to a pre-specified link among multiple physical links. A frame distribution method using tagging is proposed for the link aggregation between 10GbE switches to solve this problem. We compared the performance of the proposed method with those of the fixed and dynamic frame distribution methods. As a result, the proposed method shows a better performance when the applied load is below 0.7 and the average length of the frames is longer than 954 bytes.

Efficient Polynomial Multiplication in Extension Field GF($p^n$) (확장체 GF($p^n$)에서 효율적인 다항식 곱셈 방법)

  • Chang Namsu;Kim Chang Han
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.42 no.5 s.335
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    • pp.23-30
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    • 2005
  • In the construction of an extension field, there is a connection between the polynomial multiplication method and the degree of polynomial. The existing methods, KO and MSK methods, efficiently reduce the complexity of coefficient-multiplication. However, when we construct the multiplication of an extension field using KO and MSK methods, the polynomials are padded with necessary number of zero coefficients in general. In this paper, we propose basic properties of KO and MSK methods and algorithm that can reduce coefficient-multiplications. The proposed algorithm is more reducible than the original KO and MSK methods. This characteristic makes the employment of this multiplier particularly suitable for applications characterized by specific space constrains, such as those based on smart cards, token hardware, mobile phone or other devices.

5-Neighbor Programmable CA based PRNG (프로그램 가능한 5-이웃 CA기반의 PRNG)

  • Choi, Un-Sook
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.2
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    • pp.357-364
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    • 2022
  • A pseudo-random number generator (PRNG) is a program used when a large amount of random numbers is needed. It is used to generate symmetric keys in symmetric key cryptography systems, generate public key pairs in public key cryptography or digital signatures, and generate columns used for padding with disposable pads. Cellular Automata (CA), which is useful for specific representing nonlinear dynamics in various scientific fields, is a discrete and abstract computational system that can be implemented in hardware and is applied as a PRNG that generates keys in cryptographic systems. In this paper, I propose an algorithm for synthesizing a programmable 5-neighbor CA based PRNG that can effectively generate a nonlinear sequence using 5-neighbor CA with the radius of the neighboring cell increased by 2.

Study on algorithm of blind modulation detector in EDGE systems (EDGE 시스템에서 블라인드 변조 검출기의 알고리즘에 관한 연구)

  • Park, Hong-Won;Moon, Hong-Youl;Woo, Sung-Hyun;Kim, Jin-Hee
    • Aerospace Engineering and Technology
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    • v.9 no.1
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    • pp.67-71
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    • 2010
  • In this study, an algorithm for blind modulation detection in EDGE systems is presented. EDGE introduces an 8PSK modulation to provide high-speed data rates in addition to the existing GSM system. A transmitter may switch dynamically the modulation and coding schemes for transmission of data according to the channel quality. To decode the data correctly, the receiver has to detect using only training sequence which modulation is being used. Basically the property of one radio block composed of four bursts to detect effectively the modulation scheme even under severe conditions is used. More specifically, the reference value calculated for received burst is accumulated with previous reference value to minimize statistically the false detection probability in one radio block. Also each burst data having different modulation from the modulation of the fourth burst is set to zero to improve the decoding performance because the reference of the fourth burst has the highest reliability.

Super High-Resolution Image Style Transfer (초-고해상도 영상 스타일 전이)

  • Kim, Yong-Goo
    • Journal of Broadcast Engineering
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    • v.27 no.1
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    • pp.104-123
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    • 2022
  • Style transfer based on neural network provides very high quality results by reflecting the high level structural characteristics of images, and thereby has recently attracted great attention. This paper deals with the problem of resolution limitation due to GPU memory in performing such neural style transfer. We can expect that the gradient operation for style transfer based on partial image, with the aid of the fixed size of receptive field, can produce the same result as the gradient operation using the entire image. Based on this idea, each component of the style transfer loss function is analyzed in this paper to obtain the necessary conditions for partitioning and padding, and to identify, among the information required for gradient calculation, the one that depends on the entire input. By structuring such information for using it as auxiliary constant input for partition-based gradient calculation, this paper develops a recursive algorithm for super high-resolution image style transfer. Since the proposed method performs style transfer by partitioning input image into the size that a GPU can handle, it can perform style transfer without the limit of the input image resolution accompanied by the GPU memory size. With the aid of such super high-resolution support, the proposed method can provide a unique style characteristics of detailed area which can only be appreciated in super high-resolution style transfer.