矢量空间秘密共享-多重签名方案

本文把矢量空间秘密共享方案与多重签名方案结合起来,提出了一种新的签名方案,即矢量空间秘密共享-多重签名方案,并对该方案的安全性进行了分析.在该方案中,任何参与者的授权子集能容易地产生群签名,而参与者的非授权子集不可能产生有效的群签名,验证者可通过验证方法验证个体签名和群签名的合法性.该方案能保证一个参与者的授权子集的群签名不能被其他参与者子集所伪造,而且可以跟踪被怀疑的伪造者并将其曝光.该方案能抵御各种可能的攻击.     

矢量空间秘密共享—多重签名文字

本文把矢量空间秘密共享方案与多重签名方案结合起来，提出了一种新的签名方案，即矢量空间秘密共享-多重签名方案，并对该方案的安全性进行了分析。在该方案中，任何参与者的授权子集能容易地产生群签名，而参与者的非授权子集不可能产生有效的群签名，验证者可通过验证方法验证个体签名和群签名的合法性。该方案能保证一个参与者的授权子集的群签名不能被其他参与者子集所伪造，而且可以跟踪被怀疑的伪造者并将其曝光。该方案能抵御各种可能的攻击。     

矢量空间RSA数字签名方案

基于矢量空间秘密共享方案和RSA签名方案提出了一种新的签名方案，即矢量空间RSA签名方案，该方案包括文献[1]中方案作为其特殊情况。在该方案中，N个参与者共享RSA签名方案的秘密密钥，能保证矢量空间访问结构I中参与者的授权子集产生有效的RSA群签名，而参与者的非授权子集不能产生有效的RSA群签名。     

一种门限代理签名方案的分析与改进

通过对Qian-cao-xue的基于双线性映射的的门限代理签名方案分析,发现该方案并不满足强不可伪造性,任何人包括原始签名人可以伪造一个有效的代理签名,同时该方案也不能抵抗原始签名人改变攻击.在此基础上提出了改进的门限代理签名方案(方案1),改进的方案克服了原方案的安全缺陷.并把矢量空间秘密共享和多重代理签名结合起来,构建了一种更为广泛的基于访问结构的多重代理签名(方案2).门限代理签名方案(方案1)成为方案2的特殊情形.方案2中任何参与者的授权子集能产生多重代理签名,而非参与者不可能产生有效的多重代理签名,接收者可以通过验证方法验证个体代理签名和多重代理签名的合法性,而且能保证任何参与者都能检测出错误的子秘密.能抵御各种可能的攻击.     

公开可验证的门限秘密共享方案

提出了一种非交互式的公开可验证的门限秘密共享方案.该方案借鉴自然进化的思想,由分享的秘密进化出所有参与者的共享,并且采用知识签名的方法保证任何一方都能公开地验证共享的正确性;反过来,基于线性方程组的求解理论,任意k个被验证有效的共享可以恢复秘密.新方案是信息论安全的,易于扩展与更新.     

一种门限的基于身份无需随机预言的签名方案

 本文针对Paterson无需随机预言的签名方案,提出了一种新的基于身份的无需随机预言的(t,n)门限签名方案,并分析了新方案的正确性和安全性.分析结果表明,在离散对数难题下,参与者能方便的产生个体签名,公开验证者可通过验证公式,决定是否接受个体签名和门限签名.而任何攻击者不能伪造个体签名,不能通过窃听个体签名、门限签名和其他公开信息得到系统秘密值,即使已知所有参与者的秘密值,也无法伪造门限签名.该方案在各种可能的攻击下是安全的.     

授权子集的群签名方案

基于有限域上的方程根提出一个新的授权子集的签名方案,参与者的签名通过方程根的性质验证,而与现有方案比较,该方案具有秘密计算复杂度低,所需公共信息量小的优点。方案的安全性是基于双线性对的DH问题的困难性。分析表明文中的方案是一个安全、有效的方案。     

矢量空间秘密共享群签名方案

本文通过引入矢量空间秘密共享技术和阈下通道技术,提出了一种新的群签名方案.在本签字体制建立后,可以加入或删除成员.一个部门只有在一定数量成员的参与下,才可以生成有效的群签名.接收者可以验证签名的有效性,但是不能判断出群签名出自哪一个部门.当有争端发生时,仲裁者可以"打开"群签名,确定签名的部门.此签字的公钥长度是独立的."打开"过程通过阈下通道实现.     

门限多重秘密共享方案

本文提出了一个门限多重秘密共享方案,其安全性依赖于RSA数字签名的安全性,即大数分解的困难性.该方案具有如下特点:参与者的子秘密可反复使用,可用来共享任意多个秘密;能有效预防管理员欺诈及参与者之间的互相欺骗;此外,在验证是否有欺诈行为存在的过程中,不需要执行交互协议.     

基于矢量空间的安全分布式签密方案

在理想矢量空间秘密共享方案的基础上,在不影响其安全强度的前提下,对Zheng[1]的签密方案进行了必要修改,构造了一种不需要可信密钥分配中心的分布式签密协议.它能够同时实现门限加密和门限签名,实现代价近似于门限签名,并且基于离散对数难解问题进行了验证构造,使得在密钥生成、分布式签密和分布式解签密中都可对参与者进行合法性验证,从而有效防止了内部欺骗.     

On the classification of ideal secret sharing schemes

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.     

Hierarchical Threshold Secret Sharing

We consider the problem of threshold secret sharing in groups with hierarchical structure. In such settings, the secret is shared among a group of participants that is partitioned into levels. The access structure is then determined by a sequence of threshold requirements: a subset of participants is authorized if it has at least k₀ 0 members from the highest level, as well as at least k₁ > k₀ members from the two highest levels and so forth. Such problems may occur in settings where the participants differ in their authority or level of confidence and the presence of higher level participants is imperative to allow the recovery of the common secret. Even though secret sharing in hierarchical groups has been studied extensively in the past, none of the existing solutions addresses the simple setting where, say, a bank transfer should be signed by three employees, at least one of whom must be a department manager. We present a perfect secret sharing scheme for this problem that, unlike most secret sharing schemes that are suitable for hierarchical structures, is ideal. As in Shamir's scheme, the secret is represented as the free coefficient of some polynomial. The novelty of our scheme is the usage of polynomial derivatives in order to generate lesser shares for participants of lower levels. Consequently, our scheme uses Birkhoff interpolation, i.e., the construction of a polynomial according to an unstructured set of point and derivative values. A substantial part of our discussion is dedicated to the question of how to assign identities to the participants from the underlying finite field so that the resulting Birkhoff interpolation problem will be well posed. In addition, we devise an ideal and efficient secret sharing scheme for the closely related hierarchical threshold access structures that were studied by Simmons and Brickell.     

基于RSA体制秘密共享体制

基于RSA体制的安全性提出了一个可防欺骗的秘密共享体制。该体制仅引入了一个时间参数就很限地解决了秘密的更新和复用问题,同时也可防止参与者对相关数据的误发,且实施起来更为简洁、有效。     

Secret image sharing scheme with hierarchical threshold access structure

A hierarchical threshold secret image sharing (HTSIS) scheme is a method to share a secret image among a set of participants with different levels of authority. Recently, Guo et al. (2012) [22] proposed a HTSIS scheme based on steganography and Birkhoff interpolation. However, their scheme does not provide the required secrecy needed for HTSIS schemes so that some non-authorized subsets of participants are able to recover parts of the secret image. In this paper, we employ cellular automata and Birkhoff interpolation to propose a secure HTSIS scheme. In the new scheme, each authorized subset of participants is able to recover both the secret and cover images losslessly whereas non-authorized subsets obtain no information about the secret image. Moreover, participants are able to detect tampering of the recovered secret image. Experimental results show that the proposed scheme outperforms Guo et al.’s approach in terms of visual quality as well.     

多分存彩色图像秘密共享（2，n）方案

文献[2]中提出了一种基于异或（XOR）操作的彩色图像秘密共享（2,n）方案,简单易于实现,但恢复密图的效果较差。通过分析此方案,文章提出一个多分存的彩色图像秘密共享（2,n）方案,通过给用户增加分存图像的方法改善了恢复密图的质量。实验分析表明所提方案不仅取得了很好的恢复效果,而且保持了安全性和算法的简单性。