A verifiable essential secret image sharing scheme based on HLRs(VESIS-(t,s,k,n))

In traditional secret image sharing schemes,a secret image is shared among shareholders who have the same position.But if the shareholders have two different positions,essential and non‐essential,it is necessary to use essential secret image sharing schemes.In this article,a verifiable essential secret image sharing scheme based on HLRs is proposed.Shareholder's share consists of two parts.The first part is produced by the shareholders,which prevents the fraud of dealers.The second part is a shadow image that is produced by using HLRs and the first part of share.The verification of the first part of the shares is done for the first time by using multilinear and bilinear maps.Also,for verifying shadow images,Bloom Filters are used for the first time.The proposed scheme is more efficient than similar schemes,and for the first part of the shares,has formal security.

Verifiable Secret Redistribution for Proactive Secret Sharing Schemes

A new scheme to verifiably redistribute a secret from the old to new shareholders without reconstruction of the secret is presented in this paper. The scheme allows redistribution between different access structures and between different threshold schemes. A point worth mentioning is that this verifiable secret redistribution (VSR) scheme can identify dishonest old shareholders during redistribution without any assumption. A certain technique is adopted to verify the correctness of the old shares of the secret. As a result, the scheme is very efficient. It can be applied to proactive secret sharing (PSS) schemes to construct more flexible and practical proactive secret sharing schemes.

Information-Theoretic Secure Verifiable Secret Sharing over RSA Modulus

The well-known non-interactive and information-theoretic secure verifiable secret sharing scheme presented by Pedersen is over a large prime. In this paper, we construct a novel non-interactive and information-theoretic verifiable secret sharing over RSA （Rivest, Shamir, Adleman） modulus and give the rigorous security proof. It is shown how to distribute a secret among a group such that any set of k parties get no information about the secret. The presented scheme is generally applied to constructions of secure distributed multiplication and threshold or forward-secure signature protocols.

Verifiable Secret Sharing Scheme Based on the Plane Parametric Curve

Verifiable secret sharing is a special kind of secret sharing. In this paper, A secure and efficient threshold secret sharing scheme is proposed by using the plane parametric curve on the basis of the principle of secret sharing. And the performance of this threshold scheme is analyzed. The results reveal that the threshold scheme has its own advantage of one-parameter representation for a master key, and it is a perfect ideal secret sharing scheme. It can easily detect cheaters by single operation in the participants so that the probability of valid cheating is less than 1/p (where p is a large prime).

ASYNCHRONOUS BYZANTINE AGREEMENT PROTOCOL BASED ON VERIFIABLE SIGNATURE SHARING

An ([n/3]-1)-resilient Asynchronous Byzantine Agreement Protocol (ABAP) that combines verifiable signature sharing and random secret sharing is proposed. The protocol works in the asynchronous network environment and produces Byzantine agreement within a fixed expected number of computational rounds. The correctness of the protocol is proved in theory.

A New Rational Secret Sharing Scheme

In this paper,we propose a new approach for rational secret sharing in game theoretic settings.The trusted center is eliminated in the secret reconstruction phase.Every player doesn’t know current round is real round or fake round.The gain of following the protocol is more than the gain of deviating,so rational player has an incentive to abide the protocol.Finally,every player can obtain the secret fairly.Our scheme is verifiable and any player’s cheating can not work.Furthermore the proposed scheme is immune to backward induction and satisfies resilient equilibrium.No player of the coalition C can do better,even if the whole coalition C cheats.Our scheme can withstand the conspiracy attack with at most m-1 players.

Cheater identifiable visual secret sharing scheme

The visual secret sharing scheme proposed by Naor and Shamir provides a way to encrypt a secret black-white image into shares. A qualified group of participants can recover the secret message without using any cryptographic computation. But the original scheme can easily be corrupted by malicious participant. We propose an extension of VSS(visual secret sharing) to identify cheaters before the secret is recovered. Without the need for any additional information and cryptographic computation, every participant can verify the validity of shares of other participants, thus the security of VSS is enhanced.

NEW SECRET SHARING SCHEME BASED ON LINEAR CODE

A secret sharing system can be damaged when the dealer cheating occurs.In this paper,two kinds of secret sharing schemes based on linear code are proposed.One is a verifiable scheme which each participant can verify his own share from dealer's distribution and ensure each participant to receive valid share.Another does not have a trusted center,here,each participant plays a dual-role as the dealer and shadow(or share) provider in the whole scheme.

Publicly Verifiable Distributed Proxy Blind Signature Scheme

In this present paper, we propose a new proxy blind signature scheme, which is publicly verifiable distributed. The algorithm uses the idea of secret sharing schemes to distribute original signer＇s ability and the power of the proxy signer, and ensure the property of publicly verifiable secret sharing schemes. A new concept ＂verifiable time period＂ is also introduced to reduce the time cost in the period of verifications and increases the efficiency of our scheme.

Efficient Data Integrity Using Enhanced Secret Sharing Scheme for MANET

Mobile Ad Hoc Networks consist of nodes which are wireless and get organized based on the transmission requirement. These nodes are mobile nodes, so they communicate with each other without any fixed access point. This type of network faces several attacks because of its mobility nature. In MANET, black hole attacks may cause packet dropping or misrouting of packets during transmission from sender to receiver. This may lead to performance degradation in the network. To surmount this issue, we propose the modified secret sharing scheme to provide the data protection from unauthorized nodes, consistency of data and genuineness. In this algorithm, initially the identification of black hole attacks is achieved and followed by data protection from malicious nodes and also this scheme checks for the reality of the data. Here, we detect the misbehaviour that is dropping or misrouting using verifiable secret sharing scheme. The proposed algorithm achieves the better packet delivery ratio, misbehaviour detection efficiency, fewer packets overhead and end-to-end delay than the existing schemes. These can be viewed in the simulation results.

基于变色龙哈希和可验证秘密共享的联盟链修改方法

区块链具有去中心化、不可篡改、可追溯等特征。现有的联盟链系统在数据上链后会全程留痕,当出现敏感信息或恶意数据时无法处理,或处理后区块链分叉、中断。针对这些问题,提出一种基于变色龙哈希和可验证秘密共享的联盟链数据修改方法。首先,把变色龙哈希的陷门再分配给身份节点,从而将发起修改者与实际修改者进行隔离;其次,为保证再分配值的正确性,将不同时间周期变色龙哈希所对应的数据设为可验证数据,用验证节点上传承诺到可验证数据,并用提案节点通过承诺验证秘密共享值;最后,为防止节点作恶,提出基于奖励金机制的数据纠正方法提高节点纠正作恶的积极性,降低作恶的可能。在中山大学区块链与智能金融研究中心InPlusLab开发的DApps数据集上进行实验的结果表明:当恶意节点数30个时,所提方法相较于用传统变色龙哈希修改联盟链数据的方法在处理恶意节点的效率方面提高了44.1%;当恶意数据量达到30条时,在处理恶意数据的时间上缩短了53.7%。

一种基于Schnorr签名的区块链预言机改进方案

区块链预言机是一种为上链数据提供可信保障的中间件,可以有效解决链上链下数据传输的信任问题。当前预言机方案大多存在成本高、容错率低、密钥泄露、数据泄漏、签名失效等问题,为此,提出一种基于Schnorr门限聚合签名的区块链预言机改进方案。通过引入可验证随机函数生成可验证随机数,解决签名过程中随机数重复或能够被预测而导致的密钥泄露问题;通过引入可验证秘密分享技术,解决签名过程中密钥分发者作恶而导致的签名失效问题。预言机通过验证密钥碎片检测密钥分发者是否作恶,验证结束后向预言机智能合约发送验证结果,当预言机智能合约收到t个验证失败的结果时向所有预言机发送消息,达成一致性共识后重启签名。在数据提交阶段,只有预言机身份验证通过时才允许其提交,以防止签名过程中的数据泄露。同时,设置预言机信誉与激励机制,保证信誉较好的预言机在有效时间内参与签名并获得奖励。实验结果表明,在预言机节点数量为50、密钥分发者作恶且恶意预言机占预言机群体总数近50%时,该方案消耗的总时间不超过200 ms,gas消耗量不超过5×10~5 wei,可以有效实现可信数据上链。

基于格的最优轮数口令认证秘密共享协议

口令认证秘密共享将口令认证和秘密共享相结合,是一个贴合实际用户需求的分布式方案。该协议允许一个用户在多个服务器间共享秘密,并且只需要记忆一个简短口令即可在后续同时完成身份验证以及秘密恢复。协议安全性保证只要敌手控制的服务器不超过阈值,敌手就不能从协议中窃取任何有关口令和秘密的信息。口令认证秘密共享方案最初基于离散对数及其变体的假设,不能抵抗量子攻击,因此找到量子安全的构造成为亟需解决的问题。ROY等人提出一种恶意安全且量子安全的构造,但其通信轮数并非最优,在有恶意敌手干扰的情况下,轮数甚至不再是常数。针对轮数优化问题,文章利用可验证不经意伪随机函数原语,给出了基于格的最优轮数的量子安全构造并严格证明了其安全性。此外,协议保证多数诚实服务器场景时,诚实用户一定能在最优轮数内成功恢复正确的秘密,具有很强的鲁棒性。

基于VSS的移动自组网密钥管理研究

移动自组网Manet是一种新型的由移动节点为了某种特定目的而彼此进行连结的网络。与一般意义的网络相比较,移动Adhoc网络通常不提供对信任中心或中心服务器的在线访问,而且由于连接1和节点失效或者节点的漫游常常呈现频繁的网络分割,所以,传统的安全策略不能直接运用于该网络,必须添加新的安全措施。该文基于Manet的安全特性,根据信任分担思想,提出了一种基于安全可验证秘密共享的密钥管理方案,即将(n,t)门限秘密共享体制与可验证秘密共享VSS(VerifiableSecretSharing)相结合,实现密钥的安全分发和安全更新。

一种基于STSS的可验证秘密分享方案

针对秘密分享体制下非诚实分发者提供错误份额无法追责的问题,提出了一种基于STSS的可验证秘密分享方案来提升不诚实参与者的检测能力.STSS方案首先让分发者通过Feldman秘密分享方案将主秘密分割成n份,所得子秘密使用SM2算法对其进行签名;其次,所得签名值(r,s)采用TEA算法进行加密得到最终份额;最后,针对秘密分享体制下非诚实分发者提供错误份额无法追责的问题,方案使用双重验证,接收者在收到分享份额后通过对称密钥解密得到签名值,对比分发者公钥,保证其在传输和存储过程中未受到篡改.需要使用主秘密时,t(t<n)位接收者参与验证秘密重构可恢复原始秘密.方案在随机预言机模型下证明了安全性,通过仿真实验表明:该方案在给定门限值和子秘密数量下运算效率较高.

MANET中基于VSS协议的分域秘密共享安全认证方案

MANET的发展已有很多年,很多相关技术都已非常成熟,但MANET中的安全问题一直都是阻碍其大规模普及应用的一个瓶颈。本文中我们将MANET网络进行分域,各个安全域相对独立进行安全认证和通信加密。引入可验证密钥共享协议(VSS)进行局部域内的密钥共享,并在安全域内进行周期的密钥更新,有效防止移动敌手攻击。在节点通信安全方面应用基于域内终端领导者(EL)的验证方案,有效防止伪终端欺骗,本文的创新点就是将密钥共享、身份认证以及通信安全综合进一个解决方案,有效利用了MANET中有限的网络资源。

一种可验证的渐进式多秘密图像共享方案

为了提高秘密图像共享方案的效率以及安全性,提出了一种可验证的渐进式多秘密图像共享方案。秘密图像共享中,通过生成的哈希值来进行秘密图像的验证。方案的恢复过程中,参与者的数量达到设定门限时可以恢复出第一张秘密图像;随着参与者的数量增多,其他秘密图像依次恢复出来,直至所有的秘密图像全部恢复出来。通过实验对比分析,所提出的方案能够对多秘密图像进行共享并验证,从而提高了秘密图像共享的效率。

A trapdoor one-way function for verifiable secret sharing

This paper proposes a(t,n)-threshold verifiable secret sharing scheme with changeable parameters based on a trapdoor one-way function.This scheme consists of a generation phase,a distribution phase,an encoding phase and a reconstruction phase.The generation and distribution phases are,respectively,based on Shamir’s and Feldman’s approaches,while the encoding phase is based on a novel trapdoor one-way function.In the reconstruction phase,the shares and reconstructed secret are validated using a cryptographic hash function.In comparison with existing schemes,the proposed scheme leaks no direct information about the secret from public information.Furthermore,unlike some existing schemes,the generation and distribution phases of the proposed scheme are both independent of the secret.This feature leads to a number of advantages over existing approaches such as the dealer’s ability to perform the following modifications without updating the shares(i)modify the secret and(ii)adjust the threshold parameters of the scheme.Furthermore,each participant receives a single share,and designated participants can be given the privilege of choosing their own shares for reconstructing a secret S.Moreover,the proposed scheme possesses a high level of security which is inherited from the schemes of Shamir and Feldman,in addition to the trapdoor one-way function and the employed cryptographic hash function.