• Title, Summary, Keyword: 비밀분산

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Improved Visual Cryptography Using Cover Images (커버영상을 이용한 개선된 시각암호)

  • Jang, Si-Hwan;Choi, Yong Soo;Kim, Hyoung Joong
    • Journal of Digital Contents Society
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    • v.13 no.4
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    • pp.531-538
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    • 2012
  • Visual cryptography is a scheme that recovers secret image through human vision by overlapping distributed share images without cryptographic operations. Distribution methods are still being developed for improving quality of shared images keeping size of images invariant and enhancing robustness against resize of images. Since visual cryptography only uses shared images, this fact is exploited to attack. From this fact, a scheme safe for sharing distributed images is needed. In this paper, a new visual cryptographic scheme using cover image is proposed. This scheme reduces the chance of detection against steganalysis and increases security. In addition, this paper shows that the proposed scheme can completely decrypt secret image without creating noise.

Secret Sharing Scheme Using Visual Cryptography (시각암호에 의한 비밀 분산법)

  • 김미라
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.7 no.4
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    • pp.37-50
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    • 1997
  • 시각암호는 기존의 비밀 분산법이 비밀을 분산/복호시의 방대한 연산량을 수반하는 것과는 달리 인간의 시각에 의해 직접 복호되기 때문에 복잡한 연산이 필요없는 방식이다. 본 논문에서는 중첩하는 슬라이드의 매수에 따라 복수의 비밀화상이 복원되는 시각암호에 대해 알아보고, 그 안전성을 검증한다. 분산하고자 하는 비밀화상의 수가 증가함에 따라 크기가 기하 급수적으로 커지기 때문에 복원화성의 인식이 어렵게 된다. 따라서 고정 가중치 부호의 해밍 거리를 조정하여 줄임으로서 복원화상의 해상도를 개선하는 방법을 제안한다.

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A Secure Model for Reading and Writing in Hadoop Distributed File System and its Evaluation (하둡 분산파일시스템에서 안전한 쓰기, 읽기 모델과 평가)

  • Pang, Sechung;Ra, Ilkyeun;Kim, Yangwoo
    • Journal of Internet Computing and Services
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    • v.13 no.5
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    • pp.55-64
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    • 2012
  • Nowadays, as Cloud computing becomes popular, a need for a DFS(distributed file system) is increased. But, in the current Cloud computing environments, there is no DFS framework that is sufficient to protect sensitive private information from attackers. Therefore, we designed and proposed a secure scheme for distributed file systems. The scheme provides confidentiality and availability for a distributed file system using a secret sharing method. In this paper, we measured the speed of encryption and decryption for our proposed method, and compared them with that of SEED algorithm which is the most popular algorithm in this field. This comparison showed the computational efficiency of our method. Moreover, the proposed secure read/write model is independent of Hadoop DFS structure so that our modified algorithm can be easily adapted for use in the HDFS. Finally, the proposed model is evaluated theoretically using performance measurement method for distributed secret sharing model.

Share Renewal Scheme in Proactive Secret Sharing for Threshold Cryptosystem (임계 암호시스템 구현을 위한 능동적 비밀 분산에서의 공유 갱신 방법)

  • 이윤호;김희열;정병천;이재원;윤현수
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.5_6
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    • pp.239-249
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    • 2003
  • The secret sharing is the basic concept of the threshold cryptosystem and has an important position in the modern cryptography. At 1995, Jarecki proposed the proactive secret sharing to be a solution of existing the mobile adversary and also proposed the share renewal scheme for (k, n) threshold scheme. For n participants in the protocol, his method needs $O(n^2)$ modular exponentiation per one participant. It is very high computational cost and is not fit for the scalable cryptosystem. In this paper, we propose the efficient share renewal scheme that need only O(n) modular exponentiation per participant. And we prove our scheme is secure if less than img ${\frac{1}{2}}$ n-1 adversaries exist and they are static adversary.

One-way hash function based on-line secret sharing which identifies all cheaters (부정한 참가자의 신분 확인이 가능한 일방향 해쉬 함수에 기반한 온라인 비밀 분산 방식)

  • 오수현;김승주;원동호
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • pp.243-252
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    • 1998
  • 비밀분산은 비밀정보의 관리나 multiparty 프로토콜, 그룹 암호방식등의 분야에서 매우 중요한 부분이다. 따라서 본 논문에서는 일방향 해쉬함수에 기반한 효율적인 온라인 비밀분산 방식을 제안하고자 한다. 제안하는 방식은 하나의 share만으로 여러 개의 비밀을 분산할 수 있고, 액세스 구조가 변하는 경우에 notice board에 공개된 값들만 변경하면 각 참가자들은 기존의 share를 그대로 사용할 수 있다. 또한 참가자들의 부정이 있는 경우 그 수에 관계없이 부정한 참가자의 신분을 밝혀낼 수 있으며, 기존의 방식보다 계산상 효율적이라는 장점이 있다.

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Design of a Secret Sharing Scheme in a Tree-structured Hierarchy (트리 형태의 계층 구조에 적용 가능한 비밀분산법의 설계)

  • Song, Yeong-Won;Park, So-Young;Lee, Sang-Ho
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.3
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    • pp.161-168
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    • 2002
  • A secret sharing scheme is a cryptographic protocol to share a secret among a set of participants P in the way that only qualified subsets of P can reconstruct the secret whereas any other subset of P, non-qualified to know the secret, cannot determine anything about the secret. In this paper, we propose a new secret sharing scheme in hierarchical groups, whose hierarchy can be represented as a tree structure. In the tree structure, participants of higher levels have priorities to reconstruct the secret over participants of lower levels. In the absence of the participant of a higher level, it is possible for this participant to delegate the ability to reconstruct the secret to the child nodes of the next lower level through the transfer of his delegation ticket. This scheme has a dynamic access structure through the recursive delegation process from the root to lower levels where participants aren't absent.

User Friendly Visual Secret Sharing Scheme (사용자 친화적인 시각 비밀 분산 방법)

  • Yoon, Eun-Jun;Lee, Gil-Je;Yoo, Kee-Young
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.5
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    • pp.472-476
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    • 2008
  • In this paper, we propose a simple and user friendly visual secret sharing scheme based on binary image. The proposed scheme is a new information hiding method which uses only bit-wise exclusive-or (XOR) operation and NOT operation to share a secret binary image information in the user friendly binary images. The proposed scheme has the following merits: (1) It provides efficient embedding and reconstruction algorithms. (2) It provides lossless and perfect reconstruction of the secret binary image. (3) It provides the detection method of its own group by sharing the user friendly image. (4) It can share same sized secret image such as original cover image unlike previous methods.

User Authentication Scheme based on Secret Sharing for Distributed File System in Hadoop (하둡의 분산 파일 시스템 구조를 고려한 비밀분산 기반의 사용자 인증 기법)

  • Kim, Su-Hyun;Lee, Im-Yeong
    • Proceedings of the Korea Information Processing Society Conference
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    • pp.740-743
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    • 2013
  • 클라우드 컴퓨팅 환경에서는 사용자의 데이터를 수많은 분산서버를 이용하여 데이터를 암호화하여 저장한다. 구글, 야후 등 글로벌 인터넷 서비스 업체들은 인터넷 서비스 플랫폼의 중요성을 인식하고 자체 연구 개발을 수행, 저가 상용 노드를 기반으로 한 대규모 클러스터 기반의 클라우드 컴퓨팅 플랫폼 기술을 개발 활용하고 있다. 이와 같이 분산 컴퓨팅 환경에서 다양한 데이터 서비스가 가능해지면서 대용량 데이터의 분산관리가 주요 이슈로 떠오르고 있다. 한편, 대용량 데이터의 다양한 이용 형태로부터 악의적인 공격자나 내부 사용자에 의한 보안 취약성 및 프라이버시 침해가 발생할 수 있다. 특히, 하둡에서 데이터 블록의 권한 제어를 위해 사용하는 블록 접근 토큰에도 다양한 보안 취약점이 발생한다. 이러한 보안 취약점을 보완하기 위해 본 논문에서는 비밀분산 기반의 블록 접근 토큰 관리 기법을 제안한다.

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Efficient Secret Sharing Data Management Scheme for Privacy Protection in Smart Grid Environment (스마트 그리드 환경에서 개인정보 보호를 위한 효율적인 비밀분산 데이터 관리 방안)

  • Lee, Sung-Yong;Yeo, Sang-Soo
    • Journal of Digital Convergence
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    • v.11 no.12
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    • pp.311-318
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    • 2013
  • It is very important to design security policy and technical framework on sensitive private data in order to protect user privacy in smart grid environment. This paper introduces secret data sharing schemes proposed for privacy protection in smart grid, and presents technical problems of them. The proposed scheme in this paper, reduces the number of rounds in sharing process and also in restoration process, and can select how many databases would be used, so eventually it shows enhancements in terms of efficiency and security.

A Secure Data Transmission Scheme Based on Secret Sharing for the Maritime Cloud Environment (해사클라우드 환경에 적합한 비밀분산 기반의 안전한 데이터 전송 기법)

  • Lee, Donghyeok;Park, Namje
    • KIISE Transactions on Computing Practices
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    • v.23 no.4
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    • pp.232-237
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    • 2017
  • The Maritime Cloud is a technology that enables the seamless exchange of information between several communication links in the maritime domain. Although research on The Maritime Cloud security is still at an early stage, furthering this knowledge is vital to securing the marine environment. In this paper, we propose a method for secure data transmission through The Maritime Cloud domain. The proposed technique, based on the "secret sharing" scheme, is delivered through specifically-dedicated geocasting software. Thus, only authorized vessels can restore the original information. The proposed method is safe from so-called "sniffing" and "man-in-the-middle" attacks.