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1.
基于单向函数的广义秘密共享方案 总被引:11,自引:0,他引:11
提出了广义秘密共享方案的概念,并给出了两个基于单向函数的广义秘密共享方案,这两个方案只需每个成员保存一个子秘密,而且每个成员的子秘密可以重复使用,并且在更新成员时无需更改每个成员的子秘密。 相似文献
2.
Strongly ideal secret sharing schemes 总被引:1,自引:0,他引:1
We define strongly ideal secret sharing schemes to be ideal secret sharing schemes in which certain natural requirements are
placed on the decoder. We prove an information-theoretic characterization of perfect schemes, and use it to determine which
access structures can be encoded by strongly ideal schemes. We also discuss a hierarchy of secret sharing schemes that are
more powerful than strongly ideal schemes. 相似文献
3.
Multiple assignment scheme for sharing secret 总被引:6,自引:0,他引:6
In a secret sharing scheme, a datumd is broken into shadows which are shared by a set of trustees. The family {P′⊆P:P′ can reconstructd} is called the access structure of the scheme. A (k, n)-threshold scheme is a secret sharing scheme having the access structure {P′⊆P: |P′|≥k}. In this paper, by observing a simple set-theoretic property of an access structure, we propose its mathematical definition.
Then we verify the definition by proving that every family satisfying the definition is realized by assigning two more shadows
of a threshold scheme to trustees.
This work was partly supported by the Telecommunications Advancement Foundation. Also the work of the second author was partly
supported by the Grant in Aid for Scientific Research of the Ministry of Education, Science and Culture of Japan under Grant
Number YSE (A) 62780017. 相似文献
4.
On the classification of ideal secret sharing schemes 总被引:13,自引:0,他引:13
In a secret sharing scheme a dealer has a secret key. There is a finite set P of participants and a set of subsets of P. A secret sharing scheme with as the access structure is a method which the dealer can use to distribute shares to each participant so that a subset of participants can determine the key if and only if that subset is in . The share of a participant is the information sent by the dealer in private to the participant. A secret sharing scheme is ideal if any subset of participants who can use their shares to determine any information about the key can in fact actually determine the key, and if the set of possible shares is the same as the set of possible keys. In this paper we show a relationship between ideal secret sharing schemes and matroids.This work was performed at the Sandia National Laboratories and was supported by the U.S. Department of Energy under Contract No. DE-AC04-76DP00789. 相似文献
5.
On the size of shares for secret sharing schemes 总被引:7,自引:0,他引:7
A secret sharing scheme permits a secret to be shared among participants in such a way that only qualified subsets of participants can recover the secret, but any nonqualified subset has absolutely no information on the secret. The set of all qualified subsets defines the access structure to the secret. Sharing schemes are useful in the management of cryptographic keys and in multiparty secure protocols.We analyze the relationships among the entropies of the sample spaces from which the shares and the secret are chosen. We show that there are access structures with four participants for which any secret sharing scheme must give to a participant a share at least 50% greater than the secret size. This is the first proof that there exist access structures for which the best achievable information rate (i.e., the ratio between the size of the secret and that of the largest share) is bounded away from 1. The bound is the best possible, as we construct a secret sharing scheme for the above access structures that meets the bound with equality.This work was partially supported by Algoritmi, Modelli di Calcolo e Sistemi Informativi of M.U.R.S.T. and by Progetto Finalizzato Sistemi Informatici e Calcolo Parallelo of C.N.R. under Grant Number 91.00939.PF69. 相似文献
6.
In this paper we study secret sharing schemes for access structures based on graphs. A secret sharing scheme enables a secret
key to be shared among a set of participants by distributing partial information called shares. Suppose we desire that some
specified pairs of participants be able to compute the key. This gives rise in a natural way to a graphG which contains these specified pairs as its edges. The secret sharing scheme is calledperfect if a pair of participants corresponding to a nonedge ofG can obtain no information regarding the key. Such a perfect secret sharing scheme can be constructed for any graph. In this
paper we study the information rate of these schemes, which measures how much information is being distributed as shares compared
with the size of the secret key. We give several constructions for secret sharing schemes that have a higher information rate
than previously known schemes. We prove the general result that, for any graphG having maximum degreed, there is a perfect secret sharing scheme realizingG in which the information rate is at least 2/(d+3). This improves the best previous general bound by a factor of almost two.
The work of E. F. Brickell was performed at the Sandia National Laboratories and was supported by the U.S. Department of Energy
under Contract Number DE-AC04-76DP00789. The research of D. R. Stinson was supported by NSERC Operating Grant A9287 and by
the Center for Communication and Information Science, University of Nebraska. 相似文献
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Pang Liaojun Sun Xi Wang Yumin 《电子科学学刊(英文版)》2006,23(5):731-735
Based on Shamir's threshold secret sharing scheme and the discrete logarithm problem, a new (t, n) threshold secret sharing scheme is proposed in this paper. In this scheme, each participant's secret shadow is selected by the participant himself, and even the secret dealer cannot gain anything about his secret shadow. All the shadows are as short as the shared secret. Each participant can share many secrets with other participants by holding only one shadow. Without extra equations and information designed for verification, each participant is able to check whether another participant provides the true information or not in the recovery phase. Unlike most of the existing schemes, it is unnecessary to maintain a secure channel between each participant and the dealer. Therefore, this scheme is very attractive, especially under the circumstances that there is no secure channel between the dealer and each participant at all. The security of this scheme is based on that of Shamir's threshold scheme and the difficulty in solving the discrete logarithm problem. Analyses show that this scheme is a computationally secure and efficient scheme. 相似文献
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This paper presents a two-layered structure for optimally sharing a secret image among s essential and n − s non-essential shared shadows using the (t, s, k, n) essential thresholds, that t essential shared shadows and totally k shared shadows are needed to recover the secret image. The presented two-layered structure includes one user-defined parameter m to determine different kinds of optimal results. m = 1 leads to minimum size of total shared shadows (ST) and size of an essential shared shadow is close to size of a non-essential shared shadow. On the other hand, m = t leads to size of an essential shared shadow being twice of size of a non-essential shared shadow to signify the importance of an essential shared shadow. Moreover, the proposed structure overcomes the threshold fulfillment problem in Chen’s scheme (Chen, 2016). Theoretical analyses and experimental results show that the proposed scheme exhibits secure with optimal sharing ratios among related works. 相似文献
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Ideal secret sharing schemes with multiple secrets 总被引:6,自引:0,他引:6
We consider secret sharing schemes which, through an initial issuing of shares to a group of participants, permit a number of different secrets to be protected. Each secret is associated with a (potentially different) access structure and a particular secret can be reconstructed by any group of participants from its associated access structure without the need for further broadcast information. We consider ideal secret sharing schemes in this more general environment. In particular, we classify the collections of access structures that can be combined in such an ideal secret sharing scheme and we provide a general method of construction for such schemes. We also explore the extent to which the results that connect ideal secret sharing schemes to matroids can be appropriately generalized.The work of the second and third authors was supported by the Australian Research Council. 相似文献
13.
Peng Li Ching-Nung Yang Chih-Cheng Wu Qian Kong Yanpeng Ma 《Journal of Visual Communication and Image Representation》2013,24(7):1106-1114
In (k, n) secret image sharing (SIS), a scheme encrypts a secret image into n shadow images. Any k or more shadow images can be collaborated together to reveal the secret image. Most of the previous SIS schemes don’t distinguish the importance of shadows. However, in some application environments, some participants are accorded special privileges due to their status or importance. Thus, some shadows may be more important than others. In this paper, we consider the (t, s, k, n) essential SIS (ESIS) scheme. All n shadows are classified into s essential shadows and (n–s) non-essential shadows. When reconstructing the secret image, the (t, s, k, n)-ESIS scheme needs k shadows, which should include at least t essential shadows. 相似文献
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对一般接入结构上的可验证多秘密分享进行了研究,给出了可适用于任意接入结构的一类可验证多秘密分享方案的构造方法。用这种方法构造的可验证多秘密分享方案具有以下性质:可在一组分享者中同时分享多个秘密;分发者发送给每一分享者的秘密份额都是可公开验证的;关于每一秘密的公开信息也是可公开验证的;恢复秘密时可防止分享者提供假的份额。分析表明,用此方法构造的可验证多秘密分享方案不仅是安全的,而且是高效的。 相似文献
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Contrary to conventional protecting data such as cryptographic techniques which encrypt the data with a secret key, secret sharing takes an approach to ensure well protection of transmitted information by allowing a secret message M to be divided into n pieces. Secret message M can be held by n participants to avoid the secret from incidentally or intentionally being lost. In a secret sharing scheme, secret information leaks from shadows, attack on shadow image, and large shadow image issues which has arisen when developing an algorithm. Although existing algorithms provide remedies for such problems, the computational complexity of existing algorithms is still questionable. Therefore, we propose a low computational complexity Quadri-Directional Searching Algorithm (QDSA) for secret image sharing. Experiment results show that the proposed algorithm ensures that generated shares are of high quality and no secret information is leaked from these shares, thus it guarantees high security of our scheme. 相似文献
19.
可防止欺诈的动态秘密分享方案 总被引:25,自引:0,他引:25
基于有限域上离散对数难解问题提出一个计算安全的动态秘密分享方案 ,本方案有效地解决了密钥的翻新与复用问题 ,其效率高且实用 ,特别是能检测伪子密 ,防止欺诈 ,且数据利用率较高。 相似文献