WSN中基于全同态加密的对偶密钥建立方案

针对Guo等人基于排列的多对称多项式方案提出一种攻击方法,证明其方案未能突破容忍门限,并不能抵御大规模节点俘获攻击。通过引入全同态加密提出一种对偶密钥建立方案,使共享密钥计算过程在加密状态下完成,.阻止了敌手获得与多项式有关的信息,成功应对了大规模节点俘获攻击。提出一种全同态加密体制的间接实现方法,降低了方案的存储及计算复杂度。分析及实验表明本方案的存储、计算和通信开销完全满足无线传感器网络的要求。     

Trivium算法的立方攻击

针对Trivium算法的立方攻击中恢复超级多项式表达式时遇到的模型求解费时问题,提出了一种快速方法,该方法结合了Delaune等人的有向图建模方法以及胡凯等人的模型分解方法。初始化845轮的Trivium算法的攻击实验结果表明,相比于公开结果,恢复超级多项式表达式的模型求解时间由约3周下降至约1周。     

两种背包型的公钥密码算法的安全性分析

背包型公钥密码体制是几个最早的公钥密码体制之一,分析其安全性十分重要。该文对两种抵抗Shamir攻击和低密度攻击的背包型公钥密码体制进行了安全性分析,提出一种新的攻击方法,指出可以利用多项式时间算法以很大的概率找到私钥,从而破解了它们。     

基于知识图谱的逻辑验证码方案

验证码是保护网络资源免受自动化脚本和恶意程序攻击的一种方式.随着人工智能和深度学习技术的不断发展,现阶段利用神经网络对图像进行识别并比较语义标签之间的相似度的方式,能够破解传统的图像验证码方案.因此,提出了一种新的基于知识图谱的逻辑验证码方案.通过在知识图谱ConceptNet中选择常识知识并用词组对其进行描述,使得使...     

基于遍历矩阵的公钥加密方案的安全性分析

针对裴士辉等构造的基于遍历矩阵的公钥加密方案,本文使用遍历矩阵性质和线性化方法,证明破解该公钥加密方案不比求解多项式有限域上离散对数问题更难,从而证明了他们关于该公钥加密方案的安全归约证明是不正确的.     

破解新型的轻量级数字签名方案

由于RSA、ECC签名方案计算效率低,不适用于无线传感器网络、低廉智能卡、无线射频RFID等特殊应用领域。为设计适用于计算能力有限的小计算设备上的签名方案,Wang等人结合散列认证技术,提出了一种新型的轻量级数字签名方案。针对该新型轻量级数字签名方案,给出了由签名公钥求解其等价签名私钥的多项式时间算法。使用等价签名私钥,对手可以对任意消息伪造签名,从而破解了他们结合散列认证技术提出的数字签名方案。     

基于硬件控制器的乱序执行抗差分功耗攻击AES芯片

本文描述了一款通过硬件控制器实现乱序执行以抵抗差分功耗攻击（DPA）的AES 芯片。 该芯片实现了高级加密标准（AES）中规定的加密和解密算法。芯片采用细粒度数据流结构, 动态发掘了算法中的字节粒度操作的并发性。文章提出了一个新颖的电路,暂存-匹配-转发 单元（HMF）,作为乱序执行的基本控制结构,将并行的操作以乱序的方式执行。该芯片已 在中芯国际（SMIC）180 纳米工艺下流片。功能测试的结果表明,128 位密钥长度下加密一 组明文的平均功耗为19nJ,裸片面积为0.43mm2。芯片抗功耗攻击的能力通过一个实际攻击 平台进行了评估。实际测试结果表明,在乱序执行情况下,在64000 条样本功耗曲线下无法 识别正确密钥。和确定操作顺序的情况相比,本文提出的通过硬件控制器实现乱序执行的方 法将破解成本至少提高21 倍。     

对比特搜索生成器的猜测确定攻击

针对具有低重量反馈多项式的比特搜索生成器(BSG),利用猜测确定攻击的思想提出了一种快速密钥恢复攻击。该算法基于BSG序列的差分构造特点,首先由截获的密钥流恢复出候选差分序列,然后用反馈多项式对候选差分序列进行校验,以此减少需要求解的L维线性方程系统的数量,从而大大减少了算法所需的复杂度。理论分析和仿真结果表明,对于反馈多项式的重量小于10的BSG,该算法明显优于现有的攻击方法。特别地当反馈多项式的重量为3时,该算法能够将最好的攻击结果O(L320.5L)降低到O(L20.5L)。     

基于DNA乱序编码和混沌映射的图像加密算法

为有效抵抗选择明文攻击,已知明文攻击等密码攻击行为,改善加密结构,解决DNA编码透明等加密问题,提出了DNA乱序编码、基于多个一维Logistic混沌映射的按位抽取算法以及一种二维混沌置乱方法。利用混沌系统按本文相应算法产生的随机矩阵,结合明文图像矩阵进行DNA乱序编码,并用二维混沌置乱进行加密图像的比特级置乱来代替DNA碱基对互补替换。实验结果及安全分析表明,该算法具有良好的加密结构,可有效抵抗各种密码攻击行为。     

一种基于EPR纠缠态的量子代理签名方案

代理签名是指能够将原始签名授权给代理人的一种特殊协议,该技术在云计算领域中能够确保信息安全和数据保密。传统的代理签名以求解数学问题的困难性为基础,一旦发明量子计算机,其就会非常容易被破解。本文提出一种新的量子代理签名方案,以量子一次一密与量子隐形传态技术为基础,可以确保系统的安全性。相比传统的基于数论的代理签名,本协议由于使用量子加密技术,能够有效抵抗Shor算法攻击;相比其他的量子签名方案,该方案能够保证接收者的不可否认性;本方案使用了一种特殊量子加密方法,从而确保接收者无法伪造签名。     

Secret image sharing scheme with hierarchical threshold access structure

A hierarchical threshold secret image sharing (HTSIS) scheme is a method to share a secret image among a set of participants with different levels of authority. Recently, Guo et al. (2012) [22] proposed a HTSIS scheme based on steganography and Birkhoff interpolation. However, their scheme does not provide the required secrecy needed for HTSIS schemes so that some non-authorized subsets of participants are able to recover parts of the secret image. In this paper, we employ cellular automata and Birkhoff interpolation to propose a secure HTSIS scheme. In the new scheme, each authorized subset of participants is able to recover both the secret and cover images losslessly whereas non-authorized subsets obtain no information about the secret image. Moreover, participants are able to detect tampering of the recovered secret image. Experimental results show that the proposed scheme outperforms Guo et al.’s approach in terms of visual quality as well.     

A reversible data hiding scheme for VQ indices using locally adaptive coding

Data hiding is designed to solve the problem of secure information exchange through public networks such as Internet. In this paper, we present an improved reversible data hiding scheme that can recover original VQ indices after data extraction. As with Chang et al.’s scheme, our proposed scheme also depends on the locally adaptive coding scheme. However, experimental results confirm that the hiding capacity of our proposed scheme is around 1.36 bpi in most digital images, which is typically higher than that of Chang et al.’s [17]. Moreover, the average compression rate that can be achieved with our proposed scheme is 0.49 bpp, which outperforms both Lin and Chang’s scheme (0.50 bpp), Tsai (0.50 bpp), Chang et al.’s scheme (0.53 bpp), and Yang and Lin’s scheme (0.53 bpp).     

Analysis and improvement on identity-based cloud data integrity verification scheme

Many individuals or businesses outsource their data to remote cloud.Cloud storage provides users the advantages of economic convenience,but data owners no longer physically control over the stored data,which introduces new security challenges,such as no security guarantees of integrity and privacy.The security of two identity-based cloud data integrity verification schemes by Zhang et al and Xu et al respectively are analysed.It shows that Zhang et al.’s scheme is subjected to secret key recovery attack for the cloud servers can recover user’s private key only utilizing stored data.And Xu et al.’s scheme cannot satisfy security requirements of soundness.Based on Xu et al.'s scheme,a modified identity-based cloud data integrity verification scheme is proposed.A comprehensive analysis shows the new scheme can provide the security requirements of soundness and privacy,and has the same communication overhead and computational cost as Xu et al.’s scheme.     

Research on area-efficient low-entropy masking scheme for AES

Based on the rotating S-box masking (RSM) proposed by Nassar et al,a low-entropy masking scheme for the advanced encryption standard (AES) was proposed.Reducing the area complexity by reusing the S-boxes,improving the hardware security by shuffling operation and improving the throughput by pipelining operation were the main idea of the proposed scheme.For the AES,the number of S-boxes could be reduced from 16 to 4 (key expansion module wasn’t included).Compared with the RSM,the combinational logic,the dedicated logic and the memory size are reduced to 69%,60% and 80% respectively.In addition,the theoretical analysis shows that the proposed scheme can resist offset based CPA attack,thus has higher security than the RSM.     

An improved dos-resistant id-based password authentication scheme without using smart card

In 2010, Hwang, et al. proposed a ‘DoS-resistant ID-based password authentication scheme using smart cards’ as an improvement of Kim-Lee-Yoo’s ‘ID-based password authentication scheme’. In this paper, we cryptanalyze Hwang, et al.’s scheme and point out that the revealed session key could threat the security of the scheme. We demonstrate that extracting information from smart cards is equal to knowing the session key. Thus known session key attacks are also effective under the assumption that the adversary could obtain the information stored in the smart cards. We proposed an improved scheme with security analysis to remedy the weaknesses of Hwang, et al.’s scheme. The new scheme does not only keep all the merits of the original, but also provides several additional phases to improve the flexibility. Finally, the improved scheme is more secure, efficient, practical, and convenient, because elliptic curve cryptosystem is introduced, the expensive smart cards and synchronized clock system are replaced by mobile devices and nonces.     

Privacy-preserving data aggregation scheme against internal attackers in smart grids

With fast advancements of communication, systems and information technologies, a smart grid (SG) could bring much convenience to users because it could provide a reliable and efficient energy service. The data aggregation (DA) scheme for the SG plays an important role in evaluating information about current energy usage. To achieve the goal of preserving users’ privacy, many DA schemes for the SG have been proposed in last decade. However, how to withstand attacks of internal adversaries is not considered in those schemes. To enhance preservation of privacy, Fan et al. proposed a DA scheme for the SG against internal adversaries. In Fan et al.’s DA scheme, blinding factors are used in evaluating information about current energy usage and the aggregator cannot get the consumption information of any individual user. Fan et al. demonstrated that their scheme was secure against various attacks. However, we find that their scheme suffers from the key leakage problem, i.e., the adversary could extract the user’s private key through the public information. To overcome such serious weakness, this paper proposes an efficient and privacy-preserving DA scheme for the SG against internal attacks. Analysis shows that the proposed DA scheme not only overcome the key leakage problem in Fan et al.’s DA scheme, but also has better performance.     

Improvement of ID-based proxy re-signature scheme with pairing-free

As an all-important cryptographical technique, proxy re-signature (PRS) is broadly applied to distributed computation, copyright transfer and hidden path transfer because it permits a proxy to translate an entity’s signature into another entity’s signature on the identical message. Most existing PRS schemes make use of time-consuming pairing computation. Recently, to discard time-consuming pairing operator and complicated certificate-management, Wang et al. proposed two efficient pairing-free ID-based PRS schemes, and declared that their schemes were provably secure in the ROM. Very unluckily, in this investigation, we point out that Wang et al.’s schemes suffer from attacks of universal forgery by analyzing their security, i.e., any one can fabricate a signature on arbitrary data. After the relevant attacks are shown, the reasons which result in such attacks are analyzed. Finally, to address the above-mentioned attacks, we put forward an improved ID-based PRS scheme. The improved scheme not only preserves all advantages of Wang et al.’s scheme, but also is demonstrated to be provably secure in the ROM. Compared with the other two ID-PRS schemes, our improved ID-PRS scheme offers more advantages in respect of the overall performance and security.

     

Cryptanalysis and improvement of a chaotic system based fragile watermarking scheme

In this paper, we analyze the security of a chaotic system based fragile watermarking scheme for image tamper detection proposed by Rawat et al. recently. Some errors and modification attack against Rawat et al.’s scheme are demonstrated. Both theoretical analysis and experimental results show that the fragile watermarking scheme is not security. Besides, improvement measure is presented to enhance the security of the fragile watermarking scheme.     

A reversible steganographic scheme for VQ indices based on locally adaptive coding

Achieving a high embedding capacity and low compression rate with a reversible data hiding method in the vector quantization (VQ) compressed domain is a technically challenging problem. This paper proposes a novel reversible steganographic scheme for VQ compressed images based on a locally adaptive data compression method. The proposed method embeds n secret bits into one VQ index of an index table in Hilbert-curve scan order. The experimental results show that the proposed method can achieve the different average embedding rates of 0.99, 1.68, 2.28, and 3.04 bit per index (bpi) and average compression rates of 0.45, 0.46, 0.5, and 0.56 bit per pixel (bpp) for n = 1, 2, 3, and 4, respectively. These results indicate that the proposed scheme is superior to Chang et al.’s scheme 1 [19], Yang and Lin’s scheme [21], and Chang et al.’s scheme 2 [24].     

An improved anonymous multi‐receiver identity‐based encryption scheme

Anonymous receiver encryption is an important cryptographic primitive. It allows a sender to use the public identities of multiple receivers to encrypt messages so that only the authorized receivers or a privileged set of users can decrypt the messages, and the identities of the receivers are not revealed. Recently, Zhang et al. proposed a novel anonymous multi‐receiver encryption scheme and claimed that their scheme could realize the receiver's identity privacy. Unfortunately, in this paper, we pointed out that the scheme by Zhang et al. did not achieve the anonymity of the receiver identity after analyzing the security of the scheme. At the same time, we give the corresponding attack. After analyzing the reason to produce such attacks, a novel anonymous multi‐receiver encryption scheme is given to achieve the anonymity of the receiver's identities. And we formally prove that the proposed scheme is semantically secure for confidentiality and receiver identities’ anonymity. The security of the scheme is based on decisional bilinear Diffie‐Hellman problem. Compared with the scheme by Zhang et al., Fan et al., Wang et al., and Chien et al., our scheme is shown to be better performance and robust security. To the best of our knowledge, our scheme is most efficient in terms of computational cost and communication overhead. Copyright © 2013 John Wiley & Sons, Ltd.