A Direct Trust dependent Link State Routing Protocol Using Route Trusts for WSNs (DTLSRP)

The traditional cryptographic security techniques are not sufficient for secure routing of message from source to destination in Wireless Sensor Networks (WSNs), because it requires sophisticated software, hardware, large memory, high processing speed and communication bandwidth. It is not economic and feasible because, depending on the application, WSN nodes are high-volume in number (hence, limited resources at each node), deployment area may be hazardous, unattended and/or hostile and sometimes dangerous. As WSNs are characterized by severely constrained resources and requirement to operate in an ad-hoc manner, security functionality implementation to protect nodes from adversary forces and secure routing of message from source node to base station has become a challenging task. In this paper, we present a direct trust dependent link state routing using route trusts which protects WSNs against routing attacks by eliminating the un-trusted nodes before making routes and finding best trustworthy route among them. We compare our work with the most prevalent routing protocols and show its benefits over them.

A Novel Direct Anonymous Attestation Protocol Based on Zero Knowledge Proof for Different Trusted Domains

In order to solve the issue that existing direct anonymous attestation (DAA) scheme can not operate effectively in different domains,based on the original DAA scheme,a novel direct anonymous attestation protocol used in multi domains environment is proposed and designed,in which,the certificate issuer located in outside of domain can be considered as a proxy server to issue the DAA certificate for valid member nodes directly.Our designed mechanism accords with present trusted computing group (TCG) international specification,and can solve the problems of practical authentication and privacy information protection between different trusted domains efficiently.Compared with present DAA scheme,in our protocol,the anonymity,unforgeability can be guaranteed,and the replay-attack also can be avoided.It has important referenced and practical application value in trusted computing field.

在线社交网络中基于多态信任融合的信任估计

为提高大型在线社交网络中信任计算方法的准确性和鲁棒性,采用共被引和转置信任传播操作,提出一种基于多态信任融合的信任估计方法估计连续信任/不信任值。结合信任者、被信任者的相邻用户的信息以及被信任者对信任者的信任,平均估计出两个用户信任或被其它用户信任的差异,以及一个用户信任另一个用户和被该用户信任的差异;利用这些差异,计算4种部分信任估计值,将这些部分估计值加权平均,得到信任者对被信任者的最终信任估计值。仿真结果表明,所提方法比其它最新的现有信任计算算法更准确和鲁棒,对应用于大型网络更高效。

An Enhanced Direct Anonymous Attestation Scheme with Mutual Authentication for Network-Connected UAV Communication Systems

In network-connected UAV(NCUAV) communication systems, user authentication is replaced by platform identity authentication and integrity check because many NC-UAVs are operated without human intervention. Direct anonymous attestation(DAA) is an attractive cryptographic scheme that provides an elegant balance between platform authentication and anonymity. However, because of the low-level computing capability and limited transmission bandwidth in UAV, the existing DAA schemes are not suitable for NC-UAV communication systems. In this paper, we propose an enhanced DAA scheme with mutual authentication(MA-DAA scheme), which meets the security requirements of NC-UAV communication systems. The proposed MA-DAA scheme, which is based on asymmetric pairings, bundles the identities of trusted platform module(TPM) and Host to solve the malicious module changing attacks. Credential randomization, batch proof and verification, and mutual authentication are realized in the MA-DAA scheme. The computational workload in TPM and Host is reduced in order to meet the low computation and resource requirements in TPM and Host.The entire scheme and protocols are presented,and the security and efficiency of the proposed MA-DAA scheme are proved and analyzed.Our experiment results also confirm the high efficiency of the proposed scheme.

A Method to Implement Full Anonymous Attestation for Trusted Computing Platform

Trusted computing （TC） technology is brought out by trusted computing group （TCG） to make computing as safe and reliable as people expect. Attestation is one main function specified by TCG, which is the means by which a trusted computer assures a remote computer whose platform is not tampered with. There are two protocols that implement attestation without disclosing the platform＇s real identity, which are Privacy CA-based protocol and direct anonymous attestation （DAA） protocol. However, in the first protocol the privacy CA is the bottleneck and the platform＇s identity will be disclosed if the privacy CA is compromise, while DAA protocol can do profiling when dealing with rogue hardware device. In this paper, we propose a DAA-extended new approach to ensure full anonymous attestation that can not only detect a rogue TPM, but also reveal rogue TPM＇s real identity.

A Secure Trust Model for P2P Systems Based on Trusted Computing

Trust is one of the most important security requirements in the design and implementation of peer-to-peer (P2P) systems. In an environment where peers' identity privacy is important, it may conflict with trustworthiness that is based on the knowledge related to the peer's identity, while identity privacy is usually achieved by hiding such knowledge. A trust model based on trusted computing (TC) technology was proposed to enhance the identity privacy of peers during the trustworthiness evaluation process between peers from different groups. The simulation results show that, the model can be implemented in an efficient way, and when the degree of anonymity within group (DAWG) is up to 0.6 and the percentage of malicious peers is up to 70%, the service selection failure rate is less than 0.15.

Efficient and Secure Multi-Signature Scheme Based on Trusted Computing

A new multi-signature scheme was proposed with the extension of the direct anonymous attestation （DAA） protocol supported by trusted computing （TC） technology. Analysis and simulation results show that the signer＇s privacy is well protected with dynamic anonymity, the public key and signatures have length independent of the number of signature members, new signers are allowed to join the signature without modifying the public key, and attacks caused by secret key dumping or leaking can be avoided.

A TRUST REGION ALGORITHM VIA BILEVEL LINEAR PROGRAMMING FOR SOLVING THE GENERAL MULTICOMMODITY MINIMAL COST FLOW PROBLEMS

This paper proposes a nonmonotonic backtracking trust region algorithm via bilevel linear programming for solving the general multicommodity minimal cost flow problems.Using the duality theory of the linear programming and convex theory,the generalized directional derivative of the general multicommodity minimal cost flow problems is derived.The global convergence and superlinear convergence rate of the proposed algorithm are established under some mild conditions.

基于社交信任的概率矩阵因子分解推荐算法

针对评分矩阵和信任矩阵的稀疏性以及推荐精度不高等问题,提出基于社交信任的概率矩阵因子分解推荐算法PMFTrustSVD。该文采用概率矩阵分解算法对信任矩阵进行分解,分别获得用户作为信任者和被信任者的潜在社交偏好;根据用户在作为信任者或被信任者时的偏好不同,将TrustSVD算法中的无向信任矩阵修正为有向矩阵;融合两种算法来预测用户的评分矩阵。在FilmTrust数据集上实验结果表明,该算法优于现有基准算法,能有效缓解用户信任矩阵稀疏的问题并提高推荐精度。

工会直选与工会信任:有调节的中介模型

职工对工会信任是工会生存和发展的先决条件,研究表明民主是促进信任产生的关键性因素。工会直选作为一种民主制度的引入,在现有制度框架内能否提升工会信任?本文在理论与文献研究的基础上,提出一个有调节的中介效应模型,并使用“中国雇主——雇员匹配数据”对其进行验证。数据分析结果表明:(1)工会直选显著正向影响工具性工会实践与工会信任;(2)工具性工会实践在工会直选与工会信任的关系中起到部分中介作用;(3)外部赋能在工会直选与工具性工会实践关系中起到正向调节作用,即获得外部赋能的企业工会,工会直选对工具性工会实践的正向影响作用更强。本研究结论为工会直选的制度绩效提供了新的证据,并进一步揭示了工会直选对工会信任的内在作用机制,这可为企业工会的改革提供理论与实践方面的参考。

适用于分布式DHR系统的可追溯直接匿名认证方案

作为拟态防御技术的基本实现模型,动态异构冗余(Dynamic Heterogeneous Redundancy,DHR)系统在分布式场景下存在通信安全问题:由于系统内缺乏对异构执行体的匿名保护措施以及诚实性度量方法,异构执行体可能在未经察觉的情况下被攻击者入侵,进而使得系统整体失效。将可信计算模块(Trusted Platform Module,TPM)引入分布式DHR系统可以缓解上述问题。然而,现有TPM标准中使用的直接匿名认证(Direct Anonymous Attestation,DAA)方案会破坏分布式DHR系统的动态反馈机制,因此无法直接应用于分布式DHR系统。为此,本文对DAA方案进行改进,提出了一种适用于分布式DHR系统的可追溯直接匿名认证方案(Traceable Direct Anonymous Authentication Scheme,Tra-DAA)。本方案在维持系统内异构执行体对外匿名的同时,为各异构执行体增加了内部追溯参数,兼容了DHR系统的动态反馈性。此外,我们引入了委托计算技术,将TPM中的计算量降到了理论最低值。安全分析证明Tra-DAA在DL、DH、DBDH和LRSW假设下具备安全性,即实现了匿名、证书不可伪造以及签名不可陷害。理论分析表明Tra-DAA相比多种代表性DAA方案在TPM运算量上具备显著优势。实验结果表明,Tra-DAA中新增的可追溯功能在整体耗时中仅占5%,且Tra-DAA的整体效率相比TPM v2.0中的DAA方案有显著提升。具体来说,在Join协议、伪名为空的Sign/Verifier协议,以及伪名不为空的Sign/Verifier协议阶段,TPM的计算耗时分别缩短了33%、50%与70%。

链式可信启动在高压直流输电控制保护主机中的应用

针对目前高压直流输电中控制保护主机自身安全防护能力弱的问题,提出基于可信平台模块(TPM)安全芯片,使用国密算法SM2、SM3、SM4构建可信根并用于身份认证。系统整体设计从硬件启动和软件启动两方面,通过身份认证和数字签名建立完整的信任链,实现了控制保护主机从硬件启动、系统加载到系统运行全过程的链式可信启动。实验结果表明,所提方案可识别固件篡改、身份伪造等风险,实现了控制保护主机的安全启动,提高了高压直流输电系统的整体防护水平。

一种基于实体上下文和时间戳的信任预测模型

信任是网络计算模式下实体交互与协同的基础,如何准确地定量表示和评估信任是研究重点。该文提出以实体上下文和时间戳为条件的信任预测模型,建立了粒度为8的信任等级空间,引入了多维测量指标度量实体交互满意度,使得满意度计算更加精确。构建了具有时间衰减性的直接信任求解方法,克服了已有模型动态适应能力不足的问题。把推荐信任划分为直接推荐和间接推荐,在直接推荐信任求解中引入实体评分相似度因子,在间接推荐信任计算中提出了基于路径衰减的方法。提出了一种分布式树型存储机制DST(Distributed Storage Tree),提高了模型的稳定性和可扩展性。模拟实验表明,与已有同类型模型相比,该模型更有效和准确地提供决策依据,并且在抑制恶意实体方面具有明显作用。

组织内信任对任务绩效的影响效应

通过问卷调查,对组织内信任与工作绩效之间的关系进行了研究。研究采用结构方程建模方法,通过建构6个嵌套模型和2个非嵌套模型,将其与假设模型进行比较验证研究假设。结果表明,个体对直接领导、同事和高层管理者的信任都会对个体的工作绩效产生影响,并且彼此间的效应相互独立,彼此互补。同时,研究也讨论了多种不同信任对个体工作行为产生影响的过程中,个体对不同对象的知觉对行为复杂影响,并发现对高层管理者信任对工作绩效的影响效应部分由对直接领导的信任中介。

一种可扩展的反馈信任信息聚合算法

针对现有的动态信任聚合算法中利用基于信任链的广播方式进行反馈信任信息搜索而导致的系统运算收敛慢、可扩展性差等问题,建立了直接信任树(DTT)的概念,并基于DTT提出了一种新的可扩展的反馈信任信息聚合算法.根据节点之间的直接信任关系构建DTT,然后利用DTT进行反馈信任信息搜索,同时引入质量因子和距离因子两个参数来自动调节聚合计算的规模.仿真实验表明,算法能够显著提高反馈信任信息聚合计算的收敛性,具有较好的恶意反馈行为检测能力,在恶意节点比率增大时,算法也表现出较强的稳健性.

基于多维信任云的信任模型研究

针对主观信任的模糊性和不确定性以及现有的基于云模型的信任模型中粒度粗糙的问题,提出了一种基于多维信任云的信任模型。首先,依据实体间的直接交互经验和交互时间,利用加权逆向云生成算法计算被评估实体的直接信任云;然后,通过评估推荐实体的推荐可信度,计算被评估实体的推荐信任云;最后,综合直接信任云和推荐信任云产生综合信任云,并依此进行可信实体的选择。仿真结果表明,基于多维信任云的信任模型能够有效地识别系统中的各类服务实体,可提高实体间的交易成功率。

基于时间因素的无线传感网络信任模型

考虑到WSN节点的交互时延和能耗问题,提出一种基于时间因素的WSN信任模型。在计算直接信任度和间接信任度时引入时间衰减因素,使离当前时刻越远的信任值衰减越大,对整体信任度的影响越小,通过反馈控制机制动态更新簇内节点和簇头节点的信任度,使整体信任值具有时效性,对节点信任度的评价更精确可靠。实验结果表明,该信任模型能够有效降低无线传感网络节点之间的交互时延并提高模型的稳定性及可靠性,在对交互时延要求较高和低能耗的WSN环境下能够发挥更好作用。

一种基于名誉的P2P网络信任管理模型

由于P2P系统的开放、匿名等特点,节点间的信任关系往往很难通过客观的信任关系建立。本文构建了一种基于实体间交易历史和推荐的信任模型,提出了依据历史交易记录来计算直接信任值的方法,定义了信任推荐和信任聚合两种运算,运用分布式哈希表来处理信任值的存储和查询,并给出了信任咨询和更新的算法。实验表明,该模型可以提供较可靠的信任推荐服务,同时能较好地消除诋毁、恶意推荐等安全问题。

基于上下文因素的P2P动态信任模型

构建一个基于上下文因素的多维度P2P信任模型,结合考虑时间衰减、交互重要性和交互次数度量实体交互信任,基于Dice相似度给出信任相似度算法,设计一种多链路反馈可信度融合算法,聚合直接交互、评价相似度和信任链传递计算实体的推荐信任,综合直接信任和推荐信任进行实体信任的评估,并提出一种新的信任更新和奖惩机制。实例分析表明,模型较好地体现了上下文因素对信任计算的影响,增强了模型在上下文因素的敏感性。