具有匿名性的可搜索加密方案

已有的可搜索加密方案(PEKS),都是实现对关键词信息的保护。一个真正安全的可搜索加密方案,在保证搜索能力的前提下,不仅要实现对关键词信息的保护,也要实现对消息查询方信息的保护。基于此,提出了具有匿名性的基于身份可搜索方案(ANO-IBEKS)的定义和构造算法。该方案可以很好的解决大量数据交给第三方服务器存储(比如网络存储)的关键词密文查询问题,可以有效的保护查询关键词和查询者身份等敏感信息,无法追踪究竟是哪个用户查询了什么信息,并且给出了方案在随机预言机模型下语义安全性的证明。

云存储环境下基于时释性加密的CP-ABE方案

云存储是未来存储业务的发展方向,数据安全是云存储客户的首要关切.密文策略属性加密(CP-ABE)算法允许数据拥有者将访问策略嵌入密文中,并结合数据访问者的密钥实施访问控制,特别适合云存储环境,但CPABE不支持与时间相关的访问控制.本文提出基于时释性加密的CP-ABE方案,通过在CP-ABE中融入时释性加密(TRE)机制来实现带有时间控制的密文共享,允许数据拥有者基于用户属性和访问时间制定更加灵活的访问策略.论文通过安全分析表明,该方案能够抵抗来自用户、云存储平台和授权机构的非法访问、非法用户的串谋攻击以及选择明文攻击.

基于混沌切换系统的语音加密

鉴于语音信号的"即时性"特点,在分析了混沌掩盖、混沌调制进行加密利弊的基础上,构造了一种混沌切换加密方案,对语音进行了更安全有效地加密.计算仿真实现了对语音信号的加密,实验表明了此方法的可行性,并对其加密解密效果、抗破译能力、同步时间以及保密强度进行了分析和比较.

Some Remarks on Cocks'Identity-Based Encryption Scheme

The theory of quadratic residues plays an important role in cryptography.In 2001,Cocks developed an identity-based encryption(IBE)scheme based on quadratic residues,resolving Shamir’s 17-year-old open problem.However,a notable drawback of Cocks’scheme is the significant expansion of the ciphertext,and some of its limitations have been addressed in subsequent research.Recently,Cotan and Teşeleanu highlighted that previous studies on Cocks’scheme relied on a trial-and-error method based on Jacobi symbols to generate the necessary parameters for the encryption process.They enhanced the encryption speed of Cocks’scheme by eliminating this trialand-error method.Based on security analysis,this study concludes that the security of Cotan-Teşeleanu’s proposal cannot be directly derived from the security of the original Cocks’scheme.Furthermore,by adopting the Cotan-Teşeleanu method and introducing an additional variable as a public element,this study develops a similar enhancement scheme that not only accelerates the encryption speed but also provides security equivalent to the original Cocks’scheme.

基于云计算背景下通信网络安全传输控制技术分析

云计算环境下,通信网络安全性和传输控制面临严峻挑战。研究探讨云计算环境中特有的安全隐患,如数据泄露和恶意攻击,并分析传统加密技术的局限性。之后,研究引入量子抗性加密、基于同态加密的隐私保护、椭圆曲线加密的轻量级认证以及智能化入侵检测等技术,并通过数学模型验证这些技术的有效性。研究发现,这些技术能够显著提升网络的安全性和传输效率,特别是在复杂多变的云计算环境下,具有广泛的应用前景。

Effect of additives on properties of aluminium titanate ceramics

The influence of some additives on bulk density,phase composition,mechanical strength and thermal shock resistance of aluminium titanate （AT） ceramics was investigated.AT ceramics with different additives of MgO,SiO2 and Fe2O3 were prepared by reaction sintering.Properties of AT ceramics were tested by using Archimedes,three-point bending and thermal cycling tests.It was found that additives of MgO,SiO2 and Fe2O3 or their compound additives are favorable to reduce the porosities of AT,enhance mechanical strength and thermal shock resistance.The role of additives can be rationalized in terms of promotion of sintering process,formation of new phases and influence on lattice constant c of AT ceramics.

暗网犯罪国际法规制的问题与进路

暗网的匿名性、加密性和跨国性特征,使暗网犯罪较一般网络犯罪更具特殊性。一般性国际刑事规则和网络犯罪国际刑事规则存在的局限性,国际软法法律拘束力的缺失,影响暗网犯罪国际法规制的效能。解决暗网犯罪国际法规制问题对技术治理、顶层设计和执法合作提出了更高要求。应确立技术和法治相结合的原则,以法律促进和保障技术发展,以技术拓展法律的规制范式;并建构和完善暗网犯罪国际治理的顶层设计,推动网络犯罪国际刑事规则中增加规定“暗网犯罪”条款和暗网犯罪国内法规制的具体化;且继续强化打击暗网犯罪国际执法合作,并将发展中国家纳入其中。

IC卡专用芯片初探

简要介绍IC卡各类芯片的基本功能及其应用。并对IC卡芯片的制造、可靠性及加密性做了探讨。

大数据环境下的安全多维数据聚合协议

针对大数据无线传感器网络(Wireless Sensor Networks,WSN)对路由聚合的同时难以保持数据机密性和完整性的问题进行研究,提出一种新的无线传感器网络隐式多维数据聚合协议,用于大数据环境下安全地聚合WSN生成的大量多维数据.该协议通过采用一种简单、轻量级的超递增序列和加性同态加密方案构造多维数据以保护数据的机密性,采用同态签名方案来保护数据的完整性,通过检查中间节点的完整性过滤虚假数据包实现数据的新鲜度.安全性分析显示该协议实现了端到端的安全性,实验结果表明:该协议降低了通信开销和能耗,提高了传感器网络的生存周期.

Dielectric properties and temperature increase characteristics of zinc oxide dust from fuming furnace

Cavity perturbation method was used to determine the dielectric properties （ε′,ε″, and tanδ） of zinc oxide dust in different apparent densities. The process was conducted to study the microwave-absorption properties of zinc oxide dust and the feasibility of microwave roasting zinc oxide dust to remove fluorine and chlorine. The dielectric constant, dielectric loss, and loss tangent were proportional to the apparent density of zinc oxide dust. The effects of sample mass and microwave power on the temperature increase characteristics under the microwave field were also studied. The results show that the apparent heating rate of the zinc oxide dust increases with the increase in microwave roasting power and decreases with the increase in the sample mass. The temperature of the samples reaches approximately 800 ＆#176;C after microwave treatment for 8 min, which indicates that the zinc oxide dust has strong microwave-absorption ability.

A Data Assured Deletion Scheme in Cloud Storage

In order to provide a practicable solution to data confidentiality in cloud storage service,a data assured deletion scheme,which achieves the fine grained access control,hopping and sniffing attacks resistance,data dynamics and deduplication,is proposed.In our scheme,data blocks are encrypted by a two-level encryption approach,in which the control keys are generated from a key derivation tree,encrypted by an All-OrNothing algorithm and then distributed into DHT network after being partitioned by secret sharing.This guarantees that only authorized users can recover the control keys and then decrypt the outsourced data in an ownerspecified data lifetime.Besides confidentiality,data dynamics and deduplication are also achieved separately by adjustment of key derivation tree and convergent encryption.The analysis and experimental results show that our scheme can satisfy its security goal and perform the assured deletion with low cost.

Attribute-Based Access Control for Multi-Authority Systems with Constant Size Ciphertext in Cloud Computing

In most existing CP-ABE schemes, there is only one authority in the system and all the public keys and private keys are issued by this authority, which incurs ciphertext size and computation costs in the encryption and decryption operations that depend at least linearly on the number of attributes involved in the access policy. We propose an efficient multi-authority CP-ABE scheme in which the authorities need not interact to generate public information during the system initialization phase. Our scheme has constant ciphertext length and a constant number of pairing computations. Our scheme can be proven CPA-secure in random oracle model under the decision q-BDHE assumption. When user's attributes revocation occurs, the scheme transfers most re-encryption work to the cloud service provider, reducing the data owner's computational cost on the premise of security. Finally the analysis and simulation result show that the schemes proposed in this thesis ensure the privacy and secure access of sensitive data stored in the cloud server, and be able to cope with the dynamic changes of users' access privileges in large-scale systems. Besides, the multi-authority ABE eliminates the key escrow problem, achieves the length of ciphertext optimization and enhances the effi ciency of the encryption and decryption operations.

Decentralized Attribute-Based Encryption and Data Sharing Scheme in Cloud Storage

In this paper, we consider the problems of data sharing between multiple distrusted authorities. Prior solutions rely on trusted third parties such as CAs, or are susceptible to collusion between malicious authorities, which can comprise the security of honest ones. In this paper, we propose a new multi-authority data sharing scheme - Decen- tralized Multi-Authority ABE （DMA）, which is derived from CP-ABE that is resilient to these types of misbehavior. Our system distin- guishes between a data owner （DO） principal and attribute authorities （AAs）： the DO owns the data but allows AAs to arbitrate access by providing attribute labels to users. The data is protected by policy encryption over these attributes. Unlike prior systems, attributes generated by AAs are not user-specific, and neither is the system susceptible to collusion between users who try to escalate their access by sharing keys. We prove our scherne correct under the Decisional Bilinear Diffie-Hellman （DBDH） assumption; we also include a com- plete end-to-end implementation that demon- strates the practical efficacy of our technique.

Towards accountable authority attribute-based encryption

An accountable authority attribute-based encryption （A-ABE） scheme is presented in this paper. The notion of accountable authority identity-based encryption （A-IBE） was first introduced by Goyal at Crypto＇07. It is a novel approach to mitigate the （inherent） key escrow problem in identity-based cryptosystems. In this work, the concept of accountable authority to attribute-based encryption （ABE） setting is generalized for the first time, and then a construction is given. The scheme non-trivially integrates an A-IBE scheme proposed by Libert et al. with an ABE scheme. In our construction, a user will be identified by a pair （ id, o~）, where id denotes the user＇ s identity and ω denotes the set of attributes associated to the user. In addition, our construction is shown to be secure under some reasonable assumptions.

Adaptively Secure Attribute-Based Encryption Supporting Attribute Revocation

Attribute revocation is inevitable and al- so important for Attribute-Based Encryption （ABE） in practice. However, little attention has been paid to this issue, and it retrains one of the rmin obsta-cles for the application of ABE. Most of existing ABE schemes support attribute revocation work under indirect revocation model such that all the users＇ private keys will be affected when the revo-cation events occur. Though some ABE schemes have realized revocation under direct revocation model such that the revocation list is embedded in the ciphertext and none of the users＇ private keys will be affected by revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or they can only be proven to be selectively secure. In this paper, we first define a model of adaptively secure ABE supporting the at- tribute revocation under direct revocation model. Then we propose a Key-Policy ABE （KP-ABE） scheme and a Ciphertext-Policy ABE （CP-ABE） scheme on composite order bilinear groups. Finally, we prove our schemes to be adaptively secure by employing the methodology of dual system eno cryption.

A Generic Construction of Ciphertext-Policy Attribute- Based Encryption Supporting Attribute Revocation

Attribute-based encryption is drawing more attention with its inherent attractive properties which are potential to be widely used in the newly developing cloud computing. However, one of the main obstacles for its application is how to revoke the attributes of the users, though some ABE schemes have realized revocation, they mostly focused on the user revocation that revokes the user＇s whole attributes, or attribute revocation under the indirect revocation model such that all the users＇ private keys will be affected by the revocation. In this paper, we define the model of CP-ABE supporting the attribute revocation under the direct revocation model, in which the revocation list is embed in the ciphertext and none of the users＇ private keys will be affected by the revocation process. Then we propose a generic construction, and prove its security with the decision q-BDHE assumption.

Attribute Based DRM Scheme with Dynamic Usage Control in Cloud Computing

In order to achieve fine-grained access control in cloud computing,existing digital rights management(DRM) schemes adopt attribute-based encryption as the main encryption primitive.However,these schemes suffer from inefficiency and cannot support dynamic updating of usage rights stored in the cloud.In this paper,we propose a novel DRM scheme with secure key management and dynamic usage control in cloud computing.We present a secure key management mechanism based on attribute-based encryption and proxy re-encryption.Only the users whose attributes satisfy the access policy of the encrypted content and who have effective usage rights can be able to recover the content encryption key and further decrypt the content.The attribute based mechanism allows the content provider to selectively provide fine-grained access control of contents among a set of users,and also enables the license server to implement immediate attribute and user revocation.Moreover,our scheme supports privacy-preserving dynamic usage control based on additive homomorphic encryption,which allows the license server in the cloud to update the users' usage rights dynamically without disclosing the plaintext.Extensive analytical results indicate that our proposed scheme is secure and efficient.

Key-insulated encryption based group key management for wireless sensor network

The key exposure problem is a practical threat for many security applications. In wireless sensor networks (WSNs), keys could be compromised easily due to its limited hardware protections. A secure group key management scheme is responsible for secure distributing group keys among valid nodes of the group. Based on the key-insulated encryption (KIE), we propose a group key management scheme (KIE-GKMS), which integrates the pair-wise key pre-distribution for WSN. The KIE-GKMS scheme updates group keys dynamically when adding or removing nodes. Moreover, the security analysis proves that the KIE-GKMS scheme not only obtains the semantic security, but also provides the forward and backward security. Finally, the theoretical analysis shows that the KIE-GKMS scheme has constant performance on both communication and storage costs in sensor nodes.

Detecting Encrypted Botnet Traffic Using Spatial-Temporal Correlation

In this paper, we to detect encrypted botnet propose a novel method traffic. During the traffic preprocessing stage, the proposed payload extraction method can identify a large amount of encrypted applications traffic. It can filter out a large amount of non-malicious traffic, greatly in, roving the detection efficiency. A Sequential Probability Ratio Test （SPRT）-based method can find spatialtemporal correlations in suspicious botnet traffic and make an accurate judgment. Experimental resuks show that the false positive and false nega- tive rates can be controlled within a certain range.