无需中央机构的电子投票协议分析

针对无需中央机构的电子投票协议——Su-协议,分析指出投票者在给出其解密选票结果的参数时,协议无法确保投票人给出的参数是正确的,攻击者可以在投票的第5步给出经过设计的参数从而可以左右系统的计票结果。据此给出针对Su-协议的3种可行的攻击：公平性攻击,选票篡改攻击和秘密性攻击。     

一种安全健壮的电子投票方案

在以往的电子投票协议中，人们着重研究了如何确保投票者的隐私以及防止签证机构作弊（当投票者放弃选举时，选票签证机构冒充投票人进行投票），但对于如何防止计票机构作弊以及有效选票是否能安全到达计票机构研究甚少。文献提出了一种基于盲签名、比特承诺的电子投票方案。投票人首先对选票进行比特承诺，由签证机构进行盲签名，随后投票者将选票解盲后发送给计票机构进行计票。该协议存在着下列问题：计票机构可以假装收到的承诺因子不正确，从而不对该选票进行计票。而投票者为了证明承诺因子的正确性，势必会暴露身份。     

无可信中心的电子投票方案*

给出一个无可信中心的电子投票方案,即使在管理机构和计票机构都不可信的情况下仍能够保证投票的安全性。该方案能够始终保证投票者的匿名性,即使选票公开,任何人都不能确定投票者的身份;解决了选票碰撞的问题,即不同的投票人必定产生不同的选票。     

一种基于门限的电子投票方案

在以往电子投票方案中,验票工作都是由一名验票员承担,该验票员若不诚实,可能不记录合法选票,却统计不合法选票。为了解决该问题,提出了一种基于门限的电子投票方案。在该方案中,验票工作需要t名验票员协作,从而使验票结果更可接受。而且,投票者公布的选票结果是选票真实内容的哈希值或者密文,没人能知道选票的真实内容,从而可以防止强迫投票者投票以及买卖投票等。     

基于半信任模型的无收据的电子投票

利用同态EIGamal加密、门限EIGamal加密和同指数知识证明等技术,给出了一种无收据的电子投票方案．该方案同时保证了选票的秘密性、广义可验证性和公平性．与以前协议不同的是,所提的方案基于半信任模型,即投票者不必无条件地信任所谓的“可信赖第三方”．文中首先给出了“半信任”的定义,然后证明了所提方案在半信任模型下该方案仍然满足无收据性,从而防止了选举中的“选票买卖”、“强迫选举”等犯罪行为．     

新的无中央机构的电子选举协议

文献[1]提出了一个无中央机构的电子投票协议,这种签名适合用在选举人在电子选举时找不到可信中心对选票进行认证的时候.但是,给出的一种攻击证明该协议是不安全的,不诚实的投票人可以控制整个选举的结果而不被其他人所察觉.针对上述缺点设计一个改进的新方案,主要引入一个不同底相同离散对数的知识证明来保证投票者给出正确的私钥.并对新方案的安全性进行了分析.最后对新方案的执行效率和还存在的缺陷进行分析.     

基于量子高维Bell态纠缠交换的分发式投票方案

利用了高维Bell态,设计一种新的量子投票方案.方案分为4个阶段:首先,高维Bell纠缠态粒子被作为投票信息载体被分发给投票者;然后投票者利用最小复杂度搜索寻找竞选者,并用相移操作投出选票;接着代理人收到选票后,运用纠缠交换过程来检测窃听,通过检查粒子的测量结果来发现是否非法攻击;最后代理人利用计票算子统计票数并公布.所有人都只知道总的投票结果,单个投票者的投票信息是保密的.协议分析了各种攻击下的抵抗,证明了这是一个合理,安全,高效的量子投票方素.     

基于同态加密的多候选人电子投票方案

电子投票因其便捷的特性,日益受到人们的青睐.然而电子投票中所暴露出来的安全问题成为人们所关注的重点,如何保证电子投票中的匿名性,公开可验证性等成为一个值得关注的问题.针对现有电子投票中存在的各种问题,基于数字签名算法和全同态加密提出了一种多候选人电子投票方案.该方案采用椭圆曲线数字签名算法解决电子投票中的身份认证问题;利用全同态加密技术实现对选票加密以及对加密选票的同态计算;为了能够对选票进行批量处理,采用SIMD技术打包选票;针对加密选票计票中存在的编解码问题设计了一种同态计票器.最后基于电子投票的八个安全特性对方案的安全性进行了分析,表明该方案是安全可行的.     

基于区块链和SM9数字签名的代理投票方案

随着互联网的普及,电子投票技术逐渐替代传统纸质投票技术。然而,传统的电子投票方案主要针对一人一票制来设计方案,在一些特殊的投票场景下,一人一票制投票方式不再适用。例如,投票者不具备专业知识却也需要投票的场景,投票者由于不能理解选举的内容而消极投票,造成选举结果不专业和不公正等问题。此外,传统的电子投票技术还存在选举过程不透明和选票不可验证等问题。针对上述问题,文章提出一种基于区块链和SM9数字签名的代理投票方案。该方案首先使用区块链技术解决选票的全局可验证问题,其次使用零知识范围证明技术解决恶意选票值的问题,然后利用基于椭圆曲线的改进ElGamal算法的同态性质实现选票加密和自计票功能,最后使用SM9数字签名算法和变色龙哈希函数设计的代理投票凭证实现投票权的转让过程。通过安全性分析,证明了文章所提方案满足鲁棒性、合法性、机密性、全局可验证性和公平性。理论分析和实验数据表明,文章所提方案性能良好,适用于需要专业知识场景下的选举。     

一种安全实用的大规模选举协议

基于强(t,n)密钥绝缘的盲签名算法和哈希函数设计了一种安全实用的大规模选举协议.与现有的电子选举协议相比,该方案增强了签证机构签名私钥的安全性,其私钥每个阶段演化一次,而计票机构的验证公钥保持不变.投票人在不同的时段申请签名和进行投票,可以有效地抵御拒绝服务攻击.同时,利用单向哈希函数的连接构造选票,保证了选票的秘密性.     

RLWE同态加密算法的多候选人电子投票协议

使用安全协议保护选民隐私、保证投票公正有效是投票电子信息化的基础,安全协议的复杂度则是电子投票应用的最大阻碍。提出了一种基于RLWE同态加密算法的多候选人电子投票协议,可支持多候选人,也能满足对选民隐私的保护。该协议利用基于RLWE的同态加密算法的加法同态性质在计票环节使用密文计票保护选民的私密,利用中国剩余定理的性质对选票进行批处理,提升计票能力。该投票协议能支持多候选人投票并最终知晓每个候选人最终票数,并设置公示机构公示投票过程中的每个步骤,用于公开验证。     

A collision-free secret ballot protocol for computerized general elections

In secret ballot protocols, the unique voting property is crucial since without it a voter may vote more than once or his ballot may collide with others and be discarded by the authority. In this paper we present a collision-free secret ballot protocol based on the uniquely blind signature technique. Our proposed scheme can be used to hold large-scale general elections because it ensures independence among voters without the need for any global computation. This scheme preserves the privacy of a voter against the authority and other voters. Robustness is ensured in that no subset of voters can corrupt or disrupt the election. The verifiability of this protocol ensures that the authority cannot present a false tally without being caught.     

一个基于安全多方求和的一票否决协议

一票否决协议在现实生活中具有重要的应用价值,现行多数协议主要基于DDH假设及零知识证明等密码学知识.提出一个一票否决协议,使得投票人只能得知议案是否一致通过,而当议案被否决时任何人都无法知道有几个人投了否决票.与一般方案相比,该方案不需可信第三方及传统加密技术等.该方案主要基于安全多方求和和多精度计算,对于n个投票人,通信和计算位复杂度均为O(n2log2n).     

一个实用的电子评审方案

电子评审是一种特殊的电子选举，由于投票人很少。直接使用现有电子选举方案很难实现安全评审．本文将改进的矩阵传送安全多方求和协议与保密比较协议相结合，采用少数服从多数的选举规则，秘密比较计票结果是否大于一个预定门限值。不泄露计票值就能得出评审结果．该方案具有投票的隐私性、无收据性、计果的保密性和无争议性等性质。满足安全评审的需求；计算代价和通信代价均低于现有方案，容易设计实用的系统．     

基于智能合约的以太币投票协议

Zhao等人提出了一个比特币投票协议,使得n个投票人能够通过投票决定两个候选人中的一个接受比特币资助.投票人首先通过秘密分享、承诺和零知识证明生成各自的投票,再通过比特币交易完成投票和比特币资助,保护了投票人的隐私.此文的工作支持n个投票人生成关于m个候选人的一般性投票,并通过智能合约完成了投票和以太币资助,同样不泄露投票人的隐私.同时,该智能合约不依赖门限签名等体制,更为高效,合约的主要业务逻辑也在检测模型工具中进行了检测.     

Towards a dichotomy for the Possible Winner problem in elections based on scoring rules

To make a joint decision, agents (or voters) are often required to provide their preferences as linear orders. To determine a winner, the given linear orders can be aggregated according to a voting protocol. However, in realistic settings, the voters may often only provide partial orders. This directly leads to the Possible Winner problem that asks, given a set of partial votes, whether a distinguished candidate can still become a winner. In this work, we consider the computational complexity of Possible Winner for the broad class of voting protocols defined by scoring rules. A scoring rule provides a score value for every position which a candidate can have in a linear order. Prominent examples include plurality, k-approval, and Borda. Generalizing previous NP-hardness results for some special cases, we settle the computational complexity for all but one scoring rule. More precisely, for an unbounded number of candidates and unweighted voters, we show that Possible Winner is NP-complete for all pure scoring rules except plurality, veto, and the scoring rule defined by the scoring vector (2,1,…,1,0), while it is solvable in polynomial time for plurality and veto.     

基于多方排序协议的安全电子投票方案

与传统投票相比较, 电子投票拥有许多优势, 也存在重要的安全问题. 电子投票的全隐私性是评估投票方案安全的重要指标, 它是指对投票者的隐私保护和候选者的隐私保护, 特别是落选者的得票数的保护. 利用可验证秘密共享的思想提出了一个安全多方排序协议, 并将它运用到电子投票中, 设计了一个新的安全的电子投票协议, 本协议具有全隐私性.     

A hybrid approach to vector-based homomorphic tallying remote voting

Vector-based homomorphic tallying remote voting schemes provide an efficient protocol for vote tallying, but they require voters to prove in zero-knowledge that the ballots they cast have been properly generated. This is usually achieved by means of the so-called zero-knowledge range proofs, which should be verified by the polling station before tallying. In this paper, we present an end-to-end verifiable hybrid proposal in which ballots are proven to be correct by making use of a zero-knowledge proof of mixing but still using a homomorphic tallying for gathering the election results. Our proposal offers all the advantages of the homomorphic tallying paradigm, while it avoids the elevated computational cost of range proofs. As a result, ballot verification performance is improved in comparison with the equivalent homomorphic systems. The proposed voting scheme is suitable for multi-candidate elections as well as for elections in which the votes have different weights.     

Computational aspects of strategic behaviour in elections with top-truncated ballots

Understanding when and how computational complexity can be used to protect elections against different manipulative actions has been a highly active research area over the past two decades. Much of this literature, however, makes the assumption that the voters or agents specify a complete preference ordering over the set of candidates. There are many multiagent systems applications, and even real-world elections, where this assumption is not warranted, and this in turn raises a series of questions on the impact of partial voting on the complexity of manipulative actions. In this paper, we focus on two of these questions. First, we address the question of how hard it is to manipulate elections when the agents specify only top-truncated ballots. Here, in particular, we look at the weighted manipulation problem—both constructive and destructive manipulation—when the voters are allowed to specify top-truncated ballots, and we provide general results for all scoring rules, for elimination versions of all scoring rules, for the plurality with runoff rule, for a family of election systems known as Copeland\(^{\alpha }\), and for the maximin protocol. The second question we address is the impact of top-truncated voting on the complexity of manipulative actions in electorates with structured preference profiles. In particular, we consider electorates that are single-peaked and we show how, for many voting protocols, allowing top-truncated voting reimposes the \(\mathcal {NP}\)-hardness shields that normally vanish in such electorates.     

Two improved two-party identity-based authenticated key agreement protocols

Many authenticated key agreement protocols based on identity information were published in recent years. Hsieh et al. presented their protocol in 2002. However, Tseng et al. found a flaw in the protocol which resulted in a key compromise impersonation attack. Later, Tseng proposed his protocol conforming which conforms to all desirable security properties and is efficient. In this paper we propose two new two-party identity-based authenticated key agreement protocols. The first is based on Hsieh et al.'s protocol and makes it immune against Tseng et al.'s attack, while the second is an efficiently improved protocol based on Tseng's protocol.