RSA可扩展公钥处理器的高速实现

RSA算法可以使用Montgomery算法来实现,但速度较慢.文中提出一种二级Montgomery模乘算法,根据算法设计高速可扩展硬件实现.算法中采用高基264,相比于另外Montgomery算法,提高了RSA算法运算的性能.在硬件方面,基于3级流水64×64位的乘法器,设计了5级流水结构的运算处理单元.该硬件系统有足够的灵活度以扩展到多种不同长度的数据运算,可以实现1 024,2 048位等不同位数RSA运算.在1 024位的情况下,最终可以达到8 800次/s的加密速度.     

椭圆曲线加密算法在移动办公系统中的应用

从移动办公的安全性要求出发,阐述了椭圆曲线及椭圆曲线加密体制的优点,主要研究了在移动办公系统中用椭圆曲线加密算法替代传统的公钥密码算法RSA的实现,并证明了在移动办公系统中椭圆曲线加密算法不仅满足移动办公的安全性要求,而且优于传统的加密算法.     

RSA公钥密码算法中大素数的生成及素性检测

通过小素数因子的幂乘积构造了一个大数并运用n-1法判定其素性.分析表明:为提高找到素数的速度,应用概率素性测试算法弃除大部分合数,对判定为素数的p进行N=2p 1的变换,再判定N是否为素数以生成安全素数,可构造RSA公钥密码中的两个大素数因子.     

Composite Chaotic Pseudo-Random Sequence Encryption Algorithm for Compressed Video

Stream cryptosystems, which implement encryption by selecting parts of the block data and header information of the compressed video stream, achieve good real-time encryption with high flexibility. Chaotic random number generator-based approaches, for example, logistics maps, are comparatively promising approachs, but are vulnerable to attacks by nonlinear dynamic forecasting. A composite chaotic cryptography scheme was developed to encrypt the compressed video with the logistics map with a Z(2^31-1) field linear congruential algorithm to strengthen the security of the mono-chaotic cryptography. The scheme maintained real-time performance and flexibility of the chaotic sequence cryptography. The scheme also integrated asymmetrical public-key cryptography and encryption and identity authentification of control parameters at the initialization phase. Encryption is performed in a layered scheme based on the importance of the data in a compressed video stream. The composite chaotic cryptography scheme has the advantage that the value and updating frequency of the control parameters can be changed online to satisfy the network requirements and the processor capability, as well as the security requirements. Cryptanalysis shows that the scheme guarantees robust security, provides good real-time performance, and has flexible implementation. Statistical evaluations and tests verify that the scheme is effective.     

基于遗传算法的背包问题求解

背包问题是计算机算法研究中NP完备类的一个困难问题,对这个问题国内外很多学者已经研究出了不少经典的方法,但是这些传统的优化方法存在一些缺点。本文介绍了近年来兴起的一种机器学习算法——遗传算法解决背包问题的基本思路,并通过实例计算证明了此方法的可行性和有效性。     

Review of public-key cryptosystem based on the error correcting code

The paper review the public-key cryptosystems based on the error correcting codes such as Goppa code, BCH code, RS code, rank distance code, algebraic geometric code as well as LDPC code, and made the comparative analyses of the merits and drawbacks of them. The cryptosystem based on Goppa code has high security, but can be achieved poor. The cryptosystems based on other error correcting codes have higher performance than Goppa code. But there are still some disadvantages to solve. At last, the paper produce an assumption of the Niederreiter cascade combination cryptosystem based on double public-keys under complex circumstances, which has higher performance and security than the traditional cryptosystems.     

A new color image cryptosystem via hyperchaos synchronization

This paper proposes a novel color image cryptosystem based on synchronization of two different six-dimensional hyperchaotic systems. In the transmitter end, we apply the drive system to generate the diffusion matrices and scrambling ones, which are used to change the image pixel value and position, respectively. Thus the ciphered image is obtained. In the receiver, synchronization of two nonidentical hyperchaotic systems can be achieved by designing the appropriate controllers. The response system is employed to yield the corresponding diffusion matrices and scrambling ones using the same generation method in the encryption algorithm. Then the cipher-image can be decrypted by the decryption algorithm, which is similar to that of the encryption process but in the reversed order. The experimental results show that the presented image cryptosystem has high security and can resist noise and crop attacks.     

基于有限非阿贝尔群的密钥交换

从一般线性群GL（n,F）和对称群Sn上的困难问题出发,构造了几个密钥交换算法,新算法具有更高的效率.同时,指出基于一般线性群的密钥交换算法的安全性直接依赖于广义矩阵覆盖问题,基于对称群的密钥交换协议的安全性直接依赖于置换群上的共轭问题.     

椭圆曲线密码的一种合适的对算法

在椭圆曲线密码的应用中,有些密码体制需要进行标量乘法对计算,通常在标量乘法计算时,任一整数对采用的是三元联合稀疏形式表示.在三元稀疏形式的基础上提出任一整数对的五元联合稀疏形式表示,并把这种形式用于快速Shamir算法计算标量乘法对,并证明五元联合稀疏形式比三元联合形式更有效.     

Optical asymmetric watermarking using modified wavelet fusion and diffractive imaging

In most of the existing image encryption algorithms the generated keys are in the form of a noise like distribution with a uniform distributed histogram. However, the noise like distribution is an apparent sign indicating the presence of the keys. If the keys are to be transferred through some communication channels, then this may lead to a security problem. This is because; the noise like features may easily catch people׳s attention and bring more attacks. To address this problem it is required to transfer the keys to some other meaningful images to disguise the attackers. The watermarking schemes are complementary to image encryption schemes. In most of the iterative encryption schemes, support constraints play an important role of the keys in order to decrypt the meaningful data. In this article, we have transferred the support constraints which are generated by axial translation of CCD camera using amplitude-, and phase- truncation approach, into different meaningful images. This has been done by developing modified fusion technique in wavelet transform domain. The second issue is, in case, the meaningful images are caught by the attacker then how to solve the copyright protection. To resolve this issue, watermark detection plays a crucial role. For this purpose, it is necessary to recover the original image using the retrieved watermarks/support constraints. To address this issue, four asymmetric keys have been generated corresponding to each watermarked image to retrieve the watermarks. For decryption, an iterative phase retrieval algorithm is applied to extract the plain-texts from corresponding retrieved watermarks.