• Title, Summary, Keyword: Secret Sharing

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Reversible Secret Image Sharing Scheme Using Histogram Shifting and Difference Expansion (히스토그램 이동과 차분을 이용한 가역 비밀 이미지 공유 기법)

  • Jeon, B.H.;Lee, G.J.;Jung, K.H.;Yoo, Kee Young
    • Journal of Korea Multimedia Society
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    • v.17 no.7
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    • pp.849-857
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    • 2014
  • In this paper, we propose a (2,2)-reversible secret image sharing scheme using histogram shifting and difference expansion. Two techniques are widely used in information hiding. Advantages of them are the low distortion between cover and stego images, and high embedding capacity. In secret image sharing procedure, unlike Shamir's secret sharing, a histogram generate that the difference value between the original image and copy image is computed by difference expansion. And then, the secret image is embedded into original and copy images by using histogram shifting. Lastly, two generated shadow images are distributed to each participant by the dealer. In the experimental results, we measure a capacity of a secret image and a distortion ratio between original image and shadow image. The results show that the embedding capacity and image distortion ratio of the proposed scheme are superior to the previous schemes.

Secret-key-sharing Cryptosystem Using Optical Phase-shifting Digital Holography

  • Jeon, Seok Hee;Gil, Sang Keun
    • Current Optics and Photonics
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    • v.3 no.2
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    • pp.119-127
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    • 2019
  • A new secret-key-sharing cryptosystem using optical phase-shifting digital holography is proposed. The proposed secret-key-sharing algorithm is based on the Diffie-Hellman key-exchange protocol, which is modified to an optical cipher system implemented by a two-step quadrature phase-shifting digital holographic encryption method using orthogonal polarization. Two unknown users' private keys are encrypted by two-step phase-shifting digital holography and are changed into three digital-hologram ciphers, which are stored by computer and are opened to a public communication network for secret-key-sharing. Two-step phase-shifting digital holograms are acquired by applying a phase step of 0 or ${\pi}/2$ in the reference beam's path. The encrypted digital hologram in the optical setup is a Fourier-transform hologram, and is recorded on CCDs with 256 quantized gray-level intensities. The digital hologram shows an analog-type noise-like randomized cipher with a two-dimensional array, which has a stronger security level than conventional electronic cryptography, due to the complexity of optical encryption, and protects against the possibility of a replay attack. Decryption with three encrypted digital holograms generates the same shared secret key for each user. Schematically, the proposed optical configuration has the advantage of producing a kind of double-key encryption, which can enhance security strength compared to the conventional Diffie-Hellman key-exchange protocol. Another advantage of the proposed secret-key-sharing cryptosystem is that it is free to change each user's private key in generating the public keys at any time. The proposed method is very effective cryptography when applied to a secret-key-exchange cryptosystem with high security strength.

A (k,t,n) verifiable multi-secret sharing scheme based on adversary structure

  • Li, Jing;Wang, Licheng;Yan, Jianhua;Niu, Xinxin;Yang, Yixian
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.12
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    • pp.4552-4567
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    • 2014
  • A (n,t,n) secret sharing scheme is to share a secret among n group members, where each member also plays a role of a dealer,and any t shares can be used to recover the secret. In this paper, we propose a strong (k,t,n) verifiable multi-secret sharing scheme, where any k out of n participants operate as dealers. The scheme realizes both threshold structure and adversary structure simultaneously, and removes a trusted third party. The secret reconstruction phase is performed using an additive homomorphism for decreasing the storage cost. Meanwhile, the scheme achieves the pre-verification property in the sense that any participant doesn't need to reveal any information about real master shares in the verification phase. We compare our proposal with the previous (n,t,n) secret sharing schemes from the perspectives of what kinds of access structures they achieve, what kinds of functionalities they support and whether heavy storage cost for secret share is required. Then it shows that our scheme takes the following advantages: (a) realizing the adversary structure, (b) allowing any k out of n participants to operate as dealers, (c) small sized secret share. Moreover, our proposed scheme is a favorable candidate to be used in many applications, such as secure multi-party computation and privacy preserving data mining, etc.

Authenticated Quantum Secret Sharing using GHZ state swapping (GHZ 상태 교환을 이용한 인증된 양자 비밀 공유)

  • Lee, Duk-Jin;Lee, Hwa-Yean;Hong, Chang-Ho;Lim, Jong-In;Yang, Hyoung-Jin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.16 no.6
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    • pp.123-134
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    • 2006
  • We propose a quantum secret sharing protocol which can authenticate more than half of members using GHZ state swapping. The Trusted Third Party, Trent can authenticate all members using previously shared ID among Trent distributing his message and the members wanting to reconstruct the message. Authenticated members can reconstruct a secret message through GHZ swapping. Moreover, this protocol is efficient to expand the number of members to arbitrary number n, so it is a close quantum secret sharing protocol to classical secret sharing protocol.

New Secret Sharing Scheme for Privacy Data Management

  • Song You-Jin;Lee Dong-Hyeok
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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    • pp.765-773
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    • 2006
  • In ubiquitous environment, private enterprise or public institution's privacy data are sometimes exposed to hackers because of the lack of the sense of information security. We apply secret sharing scheme to solve the privacy problems. But, the existing secret sharing scheme are not suitable for the management of large a quantity of data because that required operation of large capacity. In this paper, We propose new secret sharing scheme for privacy data management. Our scheme makes high-speed operation possible, and it also allows for set weight for each secret pieces depending on weight of participants. The scheme proposed in this paper makes it efficient to collect and manage secure privacy data in ubiquitous environment.

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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.

Efficient On-line Secret Sharing scheme based on One-way Hash Function (일반향 해쉬 함수에 기반한 효율적인 온라인 비밀분산 방식)

  • Oh, Soo-Hyun;Kim, Seung-Joo;Won, Dong-Ho
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.10
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    • pp.3128-3137
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    • 2000
  • Secret sharing scheme is a cryptographic protocol in which a dealer distribures shares of a secret among a set of participants such that only authorized set of participants can recover the secret at a later. Secret sharing is an important cryptographic primitive in management of secret information, secure multiparty protocol and group-oriented cryptography, etc. In this paper, we propose an efficient, on-line secret sharing scheme based on one-way hash function. This scheme provides the property to share multiple secrets and allows participants to be added/deleted dynamically, without having to redistributo new shares. Proposed scheme has advantage to detect cheating and identify of all cheater, regardless of then number. Frthermore, it is more eficient than previous schemes.

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The Key Management System using the Secret Sharing Scheme Applicable to Smart Card (스마트 카드에 적용 가능한 비밀분산법을 이용한 키 관리 시스템)

  • Son, Young-Seol;Lee, Dong-Hoon
    • The KIPS Transactions:PartC
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    • v.11C no.5
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    • pp.585-594
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    • 2004
  • When several service providers want to work together with only one master key, they need to properly distribute the key to participants who come in for the co-work business and then securely manage the distributed keys. This paper describes the system that can efficiently and securely manage the master key on the basis of the secret sharing scheme that can reconstruct original secret information as the necessity of reconstructing original secret arises. The proposed system can distribute secret information to several groups and also redistribute the secret to subgroup in proportion to the participant's security level using smart card-based (t, t)-(k, n)-threshold secret scheme for securely keeping secret information and authentication of participant's identification.

New Construction of (2,n) Visual Cryptography for Multiple Secret Sharing (복수의 비밀 분산을 위한 (2, n) 시각 암호의 새로운 구성)

  • 김문수
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.10 no.3
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    • pp.37-48
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    • 2000
  • 서울Visual cryptography scheme is a simple method in which can be directly decoded the secret information in human visual system without performing any cryptographic computations. This scheme is a kind of secret sharing scheme in which if a secret of image type is scattered to n random images(slides) and any threshold (or more) of them are stacked together the original image will become visible. In this paper we consider (2, n) visual cryptography scheme and propose a new construction method in which the number of expanded pixels can be reduced by using the sample matrix. The proposed scheme can futhermore distribute the multiple secret image to each group according to the difference of relative contrast.

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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.