广义椭圆曲线数字签名链口令认证方案

一次性口令是身份认证的重要技术。文章构造了一个基于椭圆曲线数字签名链的一次性口令认证和密钥协商方案。该方案使用了具有消息恢复功能、无须求逆的椭圆曲线数字签名算法,椭圆曲线认证密钥协商协议,密钥进化算法和椭圆曲线数字签名链等。方案有以下优点:服务器无需维护口令和验证列表;允许用户自主选择和更改口令,实现了双向认证;无需系统时钟同步和传输时延限制;能够抵抗重放攻击、离线字典攻击、中间人攻击和内部人攻击;具备口令错误敏感性和强安全修复性;生成的会话密钥具有新鲜性、机密性、已知密钥安全性和前向安全性。经对比,该方案具有更好的安全性能,适合强安全性需求的场合。     

A Layer-Cluster Key Agreement Protocol for Ad Hoc Networks

Mobile ad hoc networks create additional challenges for implementing the group key establishment due to resource constraints on nodes and dynamic changes on topology. The nodes in mobile ad hoc networks are usually low power devices that run on battery power. As a result, the costs of the node resources should be minimized when constructing a group key agreement protocol so that the battery life could be prolonged. To achieve this goal, in this paper we propose a security efficient group key agreement protocol based on Burmester-Desmedt (BD) scheme and layer-cluster group model, referred to as LCKM-BD, which is appropriate for large mobile ad hoc networks. In the layer-cluster group model, BD scheme is employed to establish group key, which can not only meet security demands of mobile ad hoc networks but also improve executing performance. Finally, the proposed protocol LCKM-BD are compared with BD, TGDH (tree-based group Diffe-Hellman), and GDH (group Diffie-Hellman) group key agreement protocols. The analysis results show that our protocol can significantly decrease both the computational overhead and communication costs with respect to these comparable protocols.     

Secure and efficient digital rights management mechanisms with privacy protection

In the Internet or cloud computing environments, service providers provide more and more content services. Users can use these convenient content services in daily life. The major data of the user are maintained by the service providers except that some personal privacy data are stored at the client device. An attacker may try to invade the systems, and it will cause the damage of users and service providers. Also, users may lose their mobile devices and then it may cause the data disclosure problem. As a result, the data and privacy protection of users become an important issue in these environments. Besides, since many mobile devices are used in these environments, secure authentication and data protection methods must be efficient in these low resource environments. In this paper, we propose an efficient and privacy protection digital rights management （DRM） scheme that users can verify the valid service servers and the service servers can ensure the legal users. Since the key delegation center of the third party has the robust security protection, our proposed scheme stores the encrypted secret keys in the key delegation center. This approach not only can reduce the storage space of the user devices, but also can recover the encrypted secret keys in the key delegation center when a user loses her/his devices for solving the device losing problem.     

A note on a provable secure encryption scheme

A Cramer-Shoup scheme was modified in a variant way.The major advantage with respect to Kurosawa-Desmedt scheme is that it saves a key parameter and produces shorter ciphertext.The proof of security shows that our scheme can be instantiated with any computational secure key derivation and message authentication functions.Thus it extends the applicability of the Kurosawa-Desmedt scheme and improves its effciency.     

Efficient and provably-secure certificateless proxy re-encryption scheme for secure cloud data sharing

In current cloud computing system, large amounts of sensitive data are shared to other cloud users. To keep these data confidentiality, data owners should encrypt their data before outsourcing. We choose proxy reencryption （PRE） as the cloud data encryption technique. In a PRE system, a semi-trusted proxy can transform a ciphertext under one public key into a ciphertext of the same message under another public key, but the proxy cannot gain any information about the message. In this paper, we propose a certificateless PRE （CL-PRE） scheme without pairings. The security of the proposed scheme can be proved to be equivalent to the computational Dire- Hellman （CDH） problem in the random oracle model. Compared with other existing CL-PRE schemes, our scheme requires less computation cost and is significantly more efficient. The new scheme does not need the public key certificates to guarantee validity of public keys and solves the key escrow problem in identity-based public key cryptography.     

Certificateless strong key-insulated signature without random oracles

It is important to ensure the private key secure in cryptosystem. To reduce the underlying danger caused by the private key leakage, Dodis et al. (2003) introduced the notion of key-insulated security. To handle the private key leakage problems in certificateless signature schemes, we propose a new certificateless strong key-insulated signature scheme. Our scheme has two desirable properties. First, its security can be proved without utilizing the random oracle model. Second, it solves the key escrow problems in identity-based key-insulated signatures (IBKISs).     

A Practical SSL Server Performance Improvement Algorithm Based on Batch RSA Decryption

The secure socket layer/ transport layer security（SSL/TLS） handshake protocol uses public key cryptographic algorithms such as RSA for key establishment. Typically, public key cryptographic algorithm is computational intensive due to the modular multiplications. Therefore, SSL/TLS servers often become swamped while performing public key decryptions when the simultaneous requests increase quickly. A batch RSA decryption algorithm was proposed. The novel algorithm provides the reasonable response time and optimizes server performance significantly. The decryption speedup is proportional to the batch size b, for instance, the speedup factor is 4, while in Shacham＇s scheme the acceleration rate is only 2.5 when b = 4.     

一个安全有效的会议密钥分配方案

提出了M．Steiner等人提出的会议密钥分配方案GDH．2存在的安全漏洞，并提出了一个新的安全有效的密钥分配方案，该方案适合多个用户通过不安全的通信网络进行信息交流。相对于GDH．2而言，本文案只以增加很小的计算量和通信负荷为代价，使安全性能得到较大的提高。     

An ID-Based Authenticated Key Agreement Protocol for Peer-to-Peer Computing

Introduction Overrecentyears,withtheemergenceofdis-tributedapplicationsovertheInternet,anewmod-elofcommunicationandcomputation,calledpeer-to-peer(P2P)computing,hasgainedgreatpopu-larity[1-3].Contrarytothetraditionalclient-server model,P2Pcomputingeliminatesthenotionof“server”,andallpeersinP2Psystemcanactas clientsandserversatthesametime.Therefore,thesinglepointoffailureandthebottleneckof“server”encounteredinthetraditionalclient-serv-ermodelcanbeeliminated,andtheperformance andreliabilit…     

具有可追查性的抗合谋攻击(t,n)门限签名方案

在分析王斌和李建华的无可信中心门限签名方案(王-李方案)以及X ie-Yu改进方案安全缺陷的基础上,提出了一种新的具有可追查性的抗合谋攻击(t,n)门限签名方案;对新方案的安全性进行了分析,并与现有方案的效率进行了比较.结果表明:该方案不仅能够从根本上抵抗合谋攻击和伪造签名攻击,而且在保证匿名性的前提下,能够真正实现签名成员身份的可追查性,同时通过构造安全的分布式密钥生成协议保证群私钥的不可知性,因此比现有方案具有更高的安全性.此外,新方案的计算量和通信量与王-李方案接近,但优于X ie-Yu方案.     

基于ECC的移动自组网成员控制方案

基于Pederson分布式密钥产生方案,采用椭圆曲线密码体制提出一个分布式密钥产生协议,该方案高效且能抵制内外恶意节点的攻击,并采用门限数字签名方案给出一个安全的移动自组网的成员控制方案.通过方案的性能和安全性分析得出结论,该成员控制策略非常适合于资源受限的移动自组网.     

Verifiably Encrypted Signatures Without Random Oracles

Introduction SincethepioneeringworkduetoBonehand Franklin[1],bilinearmapshavebecomeaveryfash-ionablebuildingblockandallowedtheopeningup ofcompletelynewterritoryincryptography,mak-ingitpossibletodesigncryptographicprimitives thatwerepreviouslyunknownorimpractical,for instance,identity-basedcryptosystem,ringsigna-tures,andshortsignatures,etc[2-6].Therearemanyapplicationsfordigitalsigna-tureswithsmallsize,suchaslow-bandwidthcom-municationenvironments.Thefirstpairing-based shortsignatureschemepro…     

无线Ad-Hoc网络密钥分发和认证机制研究

针对Ad Hoc网络没有管理中心,资源受限等特点,解决了Ad-Hoc网络面临的新的安全问题,使Ad-Hoc网络得到更广泛的应用.结合基于身份加密和门限秘密共享两个基本理论,提出了一个适用于Ad-Hoc网络、没有管理中心的分布式密钥分发和认证方案.其优点是:减少了运算量,节省了存储空间和带宽,并无需在网络形成之前假设密钥已经分发完毕,从而有效解决了Ad-Hoc网络安全中密钥管理的问题.     

无线Ad-Hoc网络密钥分发和认证机制研究

针对Ad Hoc网络没有管理中心,资源受限等特点,解决了Ad-Hoc网络面临的新的安全问题,使Ad-Hoc网络得到更广泛的应用.结合基于身份加密和门限秘密共享两个基本理论,提出了一个适用于Ad-Hoc网络、没有管理中心的分布式密钥分发和认证方案.其优点是:减少了运算量,节省了存储空间和带宽,并无需在网络形成之前假设密钥已经分发完毕,从而有效解决了Ad-Hoc网络安全中密钥管理的问题.     

Robust password and smart card based authentication scheme with smart card revocation

User authentication scheme allows user and server to authenticate each other, and generates a session key for the subsequent communication. How to resist the password guessing attacks and smart card stolen attacks are two key problems for designing smart cart and password based user authentication scheme. In 2011, Li and Lee proposed a new smart cart and password based user authentication scheme with smart card revocation, and claimed that their scheme could be immunity to these attacks. In this paper, we show that Li and Lee＇s sctleme is vulnerable to off-line password guessing attack once the information stored in smart card is extracted, and it does not provide perfect forward secrecy. A robust user authentication scheme with smart card revocation is then proposed. We use a most popular and widely used formal verification tool ProVerif, which is based on applied pi calculus, to prove that the proposed scheme achieves security and authentication.     

Analysis of Information Leakage in Quantum Key Agreement

Introduction Quantumkeyagreement(QKA)enablestwo userstosharesecretrandombitsthroughaquan-tumchannel.Thesesecretbitscanbeusedasa conventionalsecretkeyforsecurecommunications overaclassicalchannel.TheadvantageofQKA overtraditionalkeyagreementmethodsisthatthe exchangeofquantumbitscanbeshowntobeun-conditionallysecure(orinformation-theoretically secure).ThefirstQKAprotocolwasproposedbyBen-nettetalinRef.[1].Bennettetalconsidered quantumkeyagreementbetweentwolegalusers AliceandBob.Thephysicalca…     

A Strategy for Middleman Attack Prevention in Remote Desktop Protocol

This paper introduces the middleman attack methods which are against the remote desktop protocol(RDP),discusses advantages and disadvantages of several current mainstream prevention strategies,and puts forward a new prevention strategy.The strategy,taking advantage of the original key agreement process of the RDP,designs a piecewise authentication scheme of the key agreement.Using the strategy can achieve the purpose of prevention and detection of middleman attacks.Finally,the security of the strategy is analyzed.     

一种高效的移动云服务环境下隐私保护认证协议

为了解决移动云服务环境的互相认证和隐私保护问题,设计了一种改进的移动云服务环境下隐私保护认证协议.该协议结合基于身份的签密技术和多服务器认证技术,保证用户只需注册一次,就可以访问多个移动云服务提供者,同时认证过程不需要可信第三方参与;该协议在移动终端未使用计算复杂度高的双线性对运算和映射到域上的hash运算,其计算效率显著提高. 通过理论分析和实验结果可知:该协议与目前已有的同类协议相比,在移动端的计算时间为45.242 s,其计算效率约为已有同类协议的2倍;具有用户匿名和不可追踪等安全性质;能够抵抗错误口令登录、更改攻击.      

代理签字算法在智能卡认证环境中的应用

智能卡可作为理想的密钥存储介质，但由于资源有限，在其内部做公钥运算效率较低。为解决这个问题，结合智能卡的特点，给出了一个基于代理签字算法的安全解决方案。实验表明，与其它方案相比具有高效的特点，同时又能保证卡内密钥信息的安全。     

Improved ID-Based Signature Scheme Solving Key Escrow

Introduction Inatraditionalpublickeycryptosystem(PKC),theassociationbetweenauser'sidentity andhispublickeyisobtainedthroughadigitalcer-tificateissuedbyacertificationauthority(CA).TheCAchecksthecredentialsofauserbeforeis-suingacertificatetohim.Tosimplifythecertifi-catemanagementprocess,Shamir[1]introducedthe conceptofID-basedcryptosystemin1984,which allowedforauser'sidentityinformationsuchas hisname,IPaddress,telephonenumber,email address,etc.toserveashispublickey.Sucha publickeyisclearlyb…