可扩展公钥密码协处理器的设计与实现

在信息安全领域中,公钥密码算法具有广泛的应用.模乘、模加(减)为公钥密码算法的关键操作,出于性能上的考虑,往往以协处理器的方式来实现这些操作.针对公钥密码算法的运算特点,本文提出了一种可扩展公钥密码协处理器体系结构以及软硬件协同流水工作方式,并且改进了模加(减)操作的实现方法,可以有效支持公钥密码算法.同时,该协处理器体系结构也可根据不同的硬件复杂度及性能设计折衷要求,进行灵活扩展.     

公钥密码中大数模幂的并行窗口算法

模乘幂运算是公钥密码体制中最常用的基本运算,提高其运算速度可有效地提高公钥密码算法的加解密效率。该文给出一种大数模乘幂的并行窗口算法,并对在曙光-2000上进行实验所得的数据进行了分析,结果表明算法是有效的。     

Montgomery exponent architecture based on programmable cellular automata

This study presents an efficient exponent architecture for public-key cryptosystems using Montgomery multiplication based on programmable cellular automata (PCA). Multiplication is the key operation in implementing circuits for cryptosystem, as the process of encrypting and decrypting a message requires modular exponentiation which can be decomposed into multiplications. Efficient multiplication algorithm and simple architecture are the key for implementing exponentiation. Thus we employ Montgomery multiplication algorithm and construct simple architecture based on irreducible all one polynomial (AOP) in GF(2^m). The proposed architecture has the advantage of high regularity and a reduced hardware complexity based on combining the characteristics of the irreducible AOP and PCA. The proposed architecture can be efficiently used for public-key cryptosystem.     

Applying systolic multiplication–inversion architectures based on modified extended Euclidean algorithm for GF(2) in elliptic curve cryptography

Elliptic curve cryptography is a very promising cryptographic method offering the same security level as traditional public key cryptosystems (RSA, El Gamal) but with considerably smaller key lengths. However, the computational complexity and hardware resources of an elliptic curve cryptosystem are very high and depend on the efficient design of EC point operations and especially point multiplication. Those operations, using the elliptic curve group law, can be analyzed in operations of the underlined GF(2^k) Field. Three basic GF(2^k) Field operations exist, addition–subtraction, multiplication and inversion–division. In this paper, we propose an optimized inversion algorithm that can be applied very well in hardware avoiding well known inversion problems. Additionally, we propose a modified version of this algorithm that apart from inversion can perform multiplication using the architectural structure of inversion. We design two architectures that use those algorithms, a two-dimensional multiplication/inversion systolic architecture and an one-dimensional multiplication/inversion systolic architecture. Based on either one of those proposed architectures a GF(2^k) arithmetic unit is also designed and used in a EC arithmetic unit that can perform all EC point operations required for EC cryptography. The EC arithmetic unit’s design methodology is proposed and analyzed and the effects of utilizing the one or two-dimensional multiplication/inversion systolic architecture are considered. The performance of the system in all its design steps is analyzed and comparisons are made with other known designs. We manage to design a GF(2^k) arithmetic unit that has the space and time complexity of an inverter but can perform all GF(2^k) operations and we show that this architecture can apply very well to an EC arithmetic unit required in elliptic curve cryptography.     

Analyzing and comparing Montgomery multiplication algorithms

Montgomery multiplication methods constitute the core of modular exponentiation, the most popular operation for encrypting and signing digital data in public-key cryptography. In this article, we study the operations involved in computing the Montgomery product, describe several high-speed, space-efficient algorithms for computing MonPro(a, b), and analyze their time and space requirements. Our focus is to collect several alternatives for Montgomery multiplication, three of which are new. However, we do not compare the Montgomery techniques to other modular multiplication approaches     

公开密钥算法芯片的设计与实现

以RSA算法为例,探讨公钥密码处理芯片的设计与优化。首先提出公钥密码芯片实现中的核心问题,即大整数模幂运算算法和大整数模乘运算算法的实现;然后针对RSA算法,提出Montgomery模乘算法的CIOS方法的一种新的快速硬件并行实现方法,其中采用加法与乘法并行运算以及多级流水线技术以提高性能,较大地减少乘法运算时间,显著提高模乘器的运算性能。     

大整数模幂的固定基窗口组合算法

模幂乘运算是实现公钥密码体制的一个很重要的运算,其运算速度从整体上决定了公钥密码体制的实现效率。通过采用预处理技术,将椭圆曲线的定点标量乘的固定基窗口方法应用在模幂运算中,与SMM算法进行组合得到一种新的求模幂乘算法——固定基窗口方法。对算法的原理与效率进行了分析,实验结果表明,算法的运算速度得到了有效提高。     

大数模幂乘动态匹配快速算法及其应用

针对 RSA、Elgamal、DSA等算法在进行数据加密或数字签名时都要进行复杂的大数模幂乘运算 ,本文分析了目前常用的几种大数模幂乘算法 ,并在此基础上提出了一种动态匹配快速算法 .实验表明 ,将该算法用于实现 RSA算法 ,其实现速度较其他算法有明显提高 .     

Binary Galois field extensions dependent multimedia data security scheme

Finite fields are widely used in modern cryptographic architecture. The prominent finite field based symmetric and asymmetric cryptosystems are (ECC) elliptic curve cryptography, RSA, (AES) advanced encryption standard and pairing-based cryptography. The arithmetic operations of a finite field performed efficiently, that meet the design space constraints and execution speed. These aims resolve tremendous challenges, which required interdisciplinary efforts to render the best algorithms, implementations, architectures, and design practices. This study proposes convenient finite field arithmetic based symmetric key cryptosystem for multimedia data security. The scheme is comprised of diffusion and confusion. To execute the diffusion phase the random numbers generation is essential in utilizing the multiplication and inversion operations over the binary Galois field extensions. The main objective of using these operations is to establish substantial randomness with less computational exertions. In addition, a block cipher construction mechanism has been deployed for the confusion phase of the algorithm which generates multiple S-boxes with fewer rounds as compared to the customary block ciphers. Therefore, efficient creation of confusion in multimedia data and hence more security is attained. The experimental results and the time complexity manifest the efficiency of the scheme against various attacks. Also, as a result of a fast and simple implementation of the binary finite field in hardware and software, the proposed cryptosystem is more convenient to implement as compared to the prevailing schemes.     

An efficient common-multiplicand-multiplication method to the Montgomery algorithm for speeding up exponentiation

The modular exponentiation is a common operation for scrambling secret data and is used by several public-key cryptosystems, such as the RSA scheme and DSS digital signature scheme. However, the calculations involved in modular exponentiation are time-consuming especially when performed in software. In this paper, we propose an efficient CMM-MSD Montgomery algorithm by utilizing the Montgomery modular reduction method, common-multiplicand-multiplication (CMM) method, and minimal-signed-digit (MSD) recoding technique for fast modular exponentiation. By using the technique of recording the common signed-digit representations in the grouped substrings of exponent, our algorithm can improve the efficiency of both the original CMM exponentiation algorithm and the Montgomery multiplication algorithm. The fast modular exponentiation algorithm developed in this paper can be easily implemented in general signed-digit computing machine, and is therefore well suited for parallel implementation to fast evaluating modular exponentiation. Moreover, by using the proposed CMM-MSD Montgomery algorithm, on average the total number of single-precision multiplications can be reduced by about 38.9% and 26.68% as compared with Dusse-Kaliski’s Montgomery algorithm and Ha-Moon’s Montgomery algorithm, respectively.     

一种高性能大数模运算单元及其应用

为了加速公钥密码系统的实现速度,设计支持大教模乘和模加减运算的模运算单元是关键.目前的方法多关注于这两种运算的分别实现,为了改善这种方式导致的硬件单元吞吐量低的问题,提出了一种流水线结构的高性能大数模运算单元.基于改进的Montgomery模乘算法,采用流水线技术,把模乘电路分成3个流水线阶段,并把模加减电路结合到第3阶段,得到一种能同时计算模乘和模加减的模运算单元.仿真结果显示,模运算单元以较少的资源占用率获得了较高的吞吐量,非常适合做高性能的公钥密码系统的基本硬件运算单元.     

大数模幂算法的分析与研究

大数模幂在密码学领域有广泛的应用，它是公钥密码的基础。文章对目前比较典型的各种大数模幂算法的设计思想进行了深入剖析，从基本设计原理和实现角度对这些模幂算法进行了整理和分类，归纳给出了各种算法的优缺点、实现方法和使用环境。     

一种适于硬件实现的快速模乘算法

RSA算法是目前应用最广泛的一种公钥加密算法,随着人们对加密安全性和加密速度要求的提高,硬件实现加密算法成了密码学应用的一个趋势。模乘算法是模幂算法的核心,基于Montgomery算法,结合Booth2算法的思想,文章给出了一种改进的高效算法,并且通过FPGA实现。对该算法和参考文献中算法的性能进行了比较,可以看出这一改进算法在速度和面积上优于现有的算法。     

基于智能卡的RSA与ECC算法的比较与实现

智能卡上的常用公钥算法为RSA和ECC算法。分别阐述了两者在带有加密协处理器的智能卡平台上的实现过程．包括RSA算法中模幂运算、模乘运算的实现；ECC算法中基域的选择、坐标系的选择、标量乘法和域算术运算的实现。并在In6neon的SLE66CLX系列智能卡芯片上实现了多种密钥长度的RSA和ECC算法，时两种算法的时间和空间效率进行了比较．根据比较结果指出了两者的优劣。     

A Synthesis of Multi-Precision Multiplication and Squaring Techniques for 8-Bit Sensor Nodes: State-of-the-Art Research and Future Challenges

Multi-precision multiplication and squaring are the performance-critical operations for the implementation of public-key cryptography, such as exponentiation in RSA, and scalar multiplication in elliptic curve cryptography (ECC). In this paper, we provide a survey on the multi-precision multiplication and squaring techniques, and make special focus on the comparison of their performance and memory footprint on sensor nodes using 8-bit processors. Different from the previous work, our advantages are in at least three aspects. Firstly, this survey includes the existing techniques for multiprecision multiplication and squaring on sensor nodes over prime fields. Secondly, we analyze and evaluate each method in a systematic and objective way. Thirdly, this survey also provides suggestions for selecting appropriate multiplication and squaring techniques for concrete implementation of public-key cryptography. At the end of this survey, we propose the research challenges on efficient implementation of the multiplication and the squaring operations based on our observation.     

Parallel modular exponentiation using load balancing without precomputation

The modular exponentiation operation of the current algorithms for asymmetric cryptography is the most expensive part in terms of computational cost. The RSA algorithm, for example, uses the modular exponentiation algorithm in encryption and decryption procedure. Thus, the overall performance of those asymmetric cryptosystems depends heavily on the performance of the specific algorithm used for modular exponentiation. This work proposes new parallel algorithms to perform this arithmetical operation and determines the optimal number of processors that yields the greatest speedup. The optimal number is obtained by balancing the processing load evenly among the processors. Practical implementations are also performed to evaluate the theoretical proposals.     

大数模乘算法的分析与研究

大数模乘在密码学领域有广泛的应用,它是RSA、ElGamal等公钥密码的基本运算。文章对目前具有典型代表性的各种大数模乘算法的设计思想进行了深入剖析,从基本设计原理和实现角度对这些模乘算法进行整理和分类,归纳并给出了各类算法的优缺点、实现方法、适用环境和研究现状。     

A method for computing Lucas sequences

Most of public-key cryptosystems rely on one-way functions, which can be used to encrypt and sign messages. Their encryption and signature operations are based on the computation of exponentiation. Recently, some public-key cryptosystems are proposed and based on Lucas functions, and the Lucas sequences are performed as S = V(d)modN. In this paper, we will transform the concept of addition chains for computing the exponentiation evaluations to the Lucas chains for computing the Lucas sequences. Theoretically, the shorter Lucas chain for d is generated, the less computation time for evaluating the value V(d) is required. Therefore, we proposed a heuristic algorithm for evaluating a shorter Lucas chain and then use it to compute the Lucas sequence with less modular multiplications.     

低功耗嵌入式平台的SM2国密算法优化实现

随着无线通信技术的发展和智能终端的普及,越来越多的密码算法被应用到物联网设备中以保障通信安全和数据安全,其中,由国家密码管理局提出的 SM2 椭圆曲线公钥密码算法作为我国自主研发的椭圆曲线公钥密码算法具有安全性高、密钥短的优点,已在通信系统中广泛部署,应用于身份认证、密钥协商等关键环节。然而,由于算法涉及有限域上的大整数运算,计算开销较大,在低功耗嵌入式平台下的执行严重影响用户体验。因此,面向ARM-m系列处理器提出了一种低功耗嵌入式平台的SM2算法的高效实现方案。具体来说,通过 Thumb-2 指令集提供的支持处理进位和节省寻址周期,对大整数的模加、模减等基础运算进行优化,并结合平台可用寄存器的数量构建高效的基础运算模块;基于ARM-m系列处理器乘累加指令周期短的特点,优化蒙哥马利乘法实现,并结合CIOS算法设计高效的模乘方案,方案不再局限于梅森素数,极大地提高了模乘计算的速度和灵活性;在理论分析和实验测试的基础上,给出了嵌入式平台上多倍点标量乘法 wNAF 滑动窗法的窗长选取方法。实验测试结果表明,可有效提升资源受限的低功耗嵌入式平台中SM2 算法的计算效率,不做预计算的情况下在 Cortex-M3 处理器上测试签名速度可达 0.204 秒/次,验签速度0.388秒/次,加密速度0.415秒/次,解密速度0.197秒/次。     

椭圆曲线加密卡设计与实现

在基于公钥密码体制电子商务中,加密卡是网络认证和通讯加密的硬件设备。文章提出一种利用椭圆曲线密码体制(ECC)加密卡硬件方案。该论文首先给出加密卡安全应用开发与设计体系结构。然后讨论了ECC的数学基础,设计了基本密码算法模型,给出ECC加密卡的各种应用。最后,讨论了加密卡设计中的几个安全问题。