On truthful auction mechanisms for electricity allocation with multiple time slots

Multimedia Tools and Applications - As technology evolves and electricity demand rises, an increasing number of researches have focused on the efficient electricity allocation mechanisms so as to...     

Strongly polynomial-time truthful mechanisms in one shot

One of the main challenges in algorithmic mechanism design is to turn (existing) efficient algorithmic solutions into efficient truthful mechanisms. Building a truthful mechanism is indeed a difficult process since the underlying algorithm must obey certain “monotonicity” properties and suitable payment functions need to be computed (this task usually represents the bottleneck in the overall time complexity).     

批验证的电子支付协议

提出一种可以批验证的多方数字签名算法,此方案的安全性是基于有限域Fp上多项式形式的离散对数。并利用此算法设计了一个公平有效的电子支付协议,此协议能够大幅度提高电子支付协议的效率。     

Pricing schemes for digital content with DRM mechanisms

In this paper, utilizing game-theoretic model, we examine the impact of collaborative structure, content quality, and network environment on the development of pricing scheme and DRM protection policy of digital content. DRM protection level decreases and pirating activities becomes relatively tolerable as the content provider and platform provider operate collaboratively. Depending on the market structure, higher content quality may strengthen or weaken the adoption of DRM. However, it would seem that, as the network environment becomes more decentralized and uncontrolled, weaker DRM protection should be a better strategy.     

Fast schemes for online record linkage

The process of integrating large volumes of data coming from disparate data sources, in order to detect records that refer to the same entities, has always been an important problem in both academia and industry. This problem becomes significantly more challenging when the integration involves a huge amount of records and needs to be conducted in a real-time fashion to address the requirements of critical applications. In this paper, we propose two novel schemes for online record linkage, which achieve very fast response times and high levels of recall and precision. Our proposed schemes embed the records into a Bloom filter space and employ the Hamming Locality-Sensitive Hashing technique for blocking. Each Bloom filter is hashed to a number of hash tables in order to amplify the probability of formulating similar Bloom filter pairs. The main theoretical premise behind our first scheme relies on the number of times a Bloom filter pair is formulated in the hash tables of the blocking mechanism. We prove that this number strongly depends on the distance of that Bloom filter pair. This correlation allows us to estimate in real-time the Hamming distances of Bloom filter pairs without performing the comparisons. The second scheme is progressive and achieves high recall, upfront during the linkage process, by continuously adjusting the sequence in which the hash tables are scanned, and also guarantees, with high probability, the identification of each similar Bloom filter pair. Our experimental evaluation, using four real-world data sets, shows that the proposed schemes outperform four state-of-the-art methods by achieving higher recall and precision, while being very efficient.     

Source code verification of a secure payment applet

This paper discusses a case study in formal verification and development of secure smart card applications. An elementary Java Card electronic purse applet is presented whose specification can be simply formulated as “in normal operation, the applet’s balance field can only be decreased, never increased”. The applet features a challenge-response mechanism which allows legitimate terminals to increase the balance by putting the applet into a special operation mode. A systematic approach is used to guarantee a secure flow of control within the applet: appropriate transition properties are first formalized as a finite state machine, then incorporated in the specification, and finally formally verified using the Loop translation tool and the PVS theorem prover.     

Query verification schemes for cloud-hosted databases: a brief survey

Database query verification schemes provide correctness guarantees for database queries. Typically such guarantees are required and advisable where queries are executed on untrusted servers. This need to verify query results, even though they may have been executed on one’s own database, is something new that has arisen with the advent of cloud services. The traditional model of hosting one’s own databases on one’s own servers did not require such verification because the hardware and software were both entirely within one’s control, and therefore fully trusted. However, with the economical and technological benefits of cloud services beckoning, many are now considering outsourcing both data and execution of database queries to the cloud, despite obvious risks. This survey paper provides an overview into the field of database query verification and explores the current state of the art in terms of query execution and correctness guarantees provided for query results. We also provide indications towards future work in the area.     

Ciphertext verification security of symmetric encryption schemes

This paper formally discusses the security problem caused by the ciphertext verification,presenting a new security notion named IND-CVA(indistinguishability under ciphertext verification attacks) to characterize the privacy of encryption schemes in this situation. Allowing the adversary to access to both encryption oracle and ciphertext verification oracle,the new notion IND-CVA is slightly stronger than IND-CPA(indistinguishability under chosen-plaintext attacks) but much weaker than IND-CCA(indistinguisha...     

面向智能终端的快捷支付“双花攻击”检测模型

双花攻击是基于去中心化结构的数字加密货币交易过程中存在的重要安全问题。主流的数字加密货币通过牺牲交易时间,等待全体节点验证的交易确认块数量达到预设值来对抗双花攻击。在手机、平板电脑等智能终端上由于硬件资源的限制以及对快捷支付的需求,以交易时间为代价的对抗方式显然无法满足应用场景的需求。对此,文章将人工免疫理论应用到数字加密货币的快捷支付中,提出一种面向智能终端的快捷支付双花攻击检测模型。该模型结合人工免疫理论,利用异常交易数据在每个交易节点训练免疫检测器,通过免疫进化与免疫应答机制对双花攻击进行快速检测并全网通报。实验结果证明,该模型能够有效预防数字加密货币快捷支付中的双花攻击。     

移动支付协议PCMS的形式化分析和验证

移动电子商务协议的形式化分析和验证是近年来移动电子商务协议的一个重要研究热点。以一个支付网关为中心的匿名的移动电子商务支付协议PCMS为研究对象,建立了PCMS协议的时间自动机模型,并用计算树逻辑CTL公式描述PCMS协议的部分性质,最后利用模型检测工具UPPAAL对PCMS协议的无死锁、时效性、有效性和钱原子性进行检测验证。验证结果表明,以支付网关为中心的匿名的安全支付协议PCMS满足无死锁、时效性、有效性和钱原子性。     

Fast verification via statistical geometric for mobile visual search

In this paper, an efficient geometric statistics method is proposed to obtain the geometric information of the object, which can achieve fast visual re-ranking along with the localization of target-of-interest. Given an input pair of images, first we get a set of interest-point correspondences, and enumerate all potential pairs in each image, upon which we calculate the statistics of the corresponding pairs to yield the geometric similarity score. We use a location geometric similarity scoring method that is invariant to rotation, scale, and translation, and can be easily incorporated in mobile visual search and augmented reality systems. Then fitting the statistics of geometric similarity scores into a Gaussian distribution that is used as a priori to determine the matching. The performance of our geometric scoring scheme is compared to the conventional geometric scoring schemes using orientation and scale. It is shown that our proposed statistically geometric method can generate fast geometric re-ranking. Meanwhile, we can accurately locate the target of search interest regardless of variations caused by occlusion and perspective changes.     

Fast in-place verification of data dependencies

Several fast and space-optimal sequential and parallel algorithms for solving the satisfaction problem of functional and multivalued dependencies (FDs and MVDs) are presented. Two frameworks to verify an MVD for a relation and their implementation by exploring the existing fast space-optimal sorting techniques are described. The space optimality means that only a constant amount of extra memory space is needed for the sequential implementations, and O(M) amount of extra memory space for parallel algorithms that use M processors. This feature makes the algorithms attractive whenever space is a critical resource and I/O transfers should be reduced to the minimal, as is often the case for relational database systems. The time requirements for in-place FD and MVD verification are given in terms of M and of N, which is the number of tuples in a relation. The effect of relation modification on FD and MVD verification is examined     

优化的匿名电子现金支付协议及其形式化验证*

针对匿名电子现金支付协议存在的缺陷,提出了一种能够满足多种安全属性的优化协议。将会话密钥的协商与使用分为两个阶段进行,确保协议密钥保密性的实现;引入电子证书证明交易主体的身份,确保协议非否认性的实现;借助可信方传递付款收据,避免交易主体不诚实所导致的公平性缺失;引入FTP传输方式传送电子货币和付款收据,确保实现可追究性与公平性,进一步增强协议的鲁棒性。对优化协议进行形式化验证,结果表明,优化协议满足密钥保密性、非否认性、公平性、可追究性、原子性等安全属性。     

基于加密短信验证码的移动安全支付解决方案

针对移动支付过程中支付验证码容易泄露的问题,提出了基于加密短信息验证码的双因素移动支付系统方案。该方案基于公开密钥系统,使用公钥基础设施/认证机构（PKI/CA）的认证方法进行服务器与客户端的在线安全认证,并且利用客户在服务器上注册的用户名、密码和加密的交易验证短信来确保即使验证码密文泄漏,攻击者也无法获取验证码,从而杜绝了验证码泄漏造成的失窃风险。仿真结果表明,加密验证码方案在使用短信接口发送给用户时,系统的反应时间与未加密验证码方案的反应时间差别并不明显,而且增长趋势保持一致,均随着用户访问量的增加呈线性增长,能够兼顾系统的安全性和有效性。     

网络商店的付费机制与信息安全分析

随着因特网的发展与普及,产生了更多的商机,造就出各种不同型态的网络商店,同时也衍生出不同的付费方式,例如电子钱包、网上银行、在线ATM等等。面对众多付费方式的选择时,不同市场必须选搭各种付费制度,当市场导入新制付费制度后,除了增加新制付费制度给予消费者选择外,并能让原来的市场消费者对于新付费机制产生消费学习性,最终消费者会依个人意志选择最利己的付费机制。通过调查分析,网络商店提供付费机制使用的便利性、易用性、实时性、精确性、安全性对消费者态度有显著正向的影响。     

基于无证书加密短信验证码的移动支付方案

针对移动支付中验证码泄露问题,提出了一种基于无双线性对的无证书公钥加密短信验证码的移动支付系统方案。该方案引入了标记化思想,双因素认证,解决了移动端私钥存储泄露问题。利用无证书公钥密码签密验证码,即使密文被泄露,攻击者也无法得到真正的验证码,从而避免了验证码泄露的风险。分析结果表明,该方案可以有效抵御多种攻击,并能对用户信息进行隐私保护,是一种安全可靠的移动支付方案。     

A mechanism that provides incentives for truthful feedback in peer-to-peer systems

We propose a mechanism for providing the incentives for reporting truthful feedback in a peer-to-peer system for exchanging services (or content). This mechanism is to complement reputation mechanisms that employ ratings’ feedback on the various transactions in order to provide incentives to peers for offering better services to others. Under our approach, each of the transacting peers (rather than just the client) submits a rating on the performance of their mutual transaction. If these are in disagreement, then both transacting peers are punished, since such an occasion is a sign that one of them is lying. The severity of each peer’s punishment is determined by his corresponding non-credibility metric; this is maintained by the mechanism and evolves according to the peer’s record. When under punishment, a peer does not transact with others. We model the punishment effect of the mechanism in a peer-to-peer system as a Markov chain that is experimentally proved to be very accurate. According to this model, the credibility mechanism leads the peer-to-peer system to a desirable steady state isolating liars. Then, we define a procedure for the optimization of the punishment parameters of the mechanism for peer-to-peer systems of various characteristics. We experimentally prove that this optimization procedure is effective and necessary for the successful employment of the mechanism in real peer-to-peer systems. Then, the optimized credibility mechanism is combined with reputation-based policies to provide a complete solution for high performance and truthful rating in peer-to-peer systems. The combined mechanism was experimentally proved to deal very effectively with large fractions of collaborated liar peers that follow static or dynamic rational lying strategies in peer-to-peer systems with dynamically renewed population, while the efficiency loss induced to sincere peers by the presence of liars is diminished. Finally, we describe the potential implementation of the mechanism in real peer-to-peer systems.