Synthesis Optimization on Galois-Field Based Arithmetic Operators for Rijndael Cipher

A  series  of  experiments  has  been  conducted  to  show  that  FPGA synthesis  of  Galois-Field  (GF)  based  arithmetic  operators  can  be  optimized automatically  to  improve  Rijndael  Cipher  throughput.  Moreover,  it  has  been demonstrated  that  efficiency  improvement  in  GF  operators  does  not  directly correspond to the system performance at application level. The experiments were motivated by so many research works that focused on improving performance of GF  operators.  Each  of  the  variants  has  the  most  efficient  form  in  either  time (fastest) or space  (smallest occupied area) when implemented in FPGA chips. In fact,  GF  operators are not utilized  individually, but  rather integrated one to the others to  implement algorithms.  Contribution  of  this  paper  is  to  raise  issue  on GF-based  application  performance  and  suggest  alternative  aspects  that potentially  affect  it.  Instead  of  focusing  on  GF  operator  efficiency,  system characteristics are worth considered in optimizing application performance

Implementaciones hardware de circuitos aritméticos sobre cuerpos finitos (Hardwareimolementations of arithmetic circuits over finite field)

La aritmética sobre cuerpos finitos ha recibido mucho interés debido a su importancia en criptografía, control de errores de codificación y procesado de señales digitales. Una gran parte del tiempo de las rutinas criptográficas se dedica al cálculo de operaciones aritméticas sobre cuerpos finitos. Los sistemas que usan esta aritmética deben ser rápidos debido a los rendimientos requeridos en los sistemas de comunicación actuales. La suma en GF(2^m) es una operación XOR binaria independiente, puede ser realizada de forma rápida y sin retardo. Sin embargo otras operaciones son mucho más complejas y con mayor retardo. La eficiencia de las implementaciones hardware se mide en términos del número de puertas (XOR y AND) y del retardo total debido a esas puertas del circuito. El objetivo de este documento es hacer un estudio comparativo de diferentes circuitos aritméticos sobre GF(2^m), se utilizarán los cuerpos recomendados por el NIST y el SECG. Por su importancia, se han estudiado diferentes implementaciones para los algoritmos de multiplicación, tanto multiplicación serie como paralela junto con multiplicación dígito serie. Para el estudio de toras operaciones aritméticas, también se estudian algoritmos para obtener el cuadrado y el inverso de elementos pertencientes a GF(2^m). Para realizar este trabajo se implentarán los algoritmos mencionados en VHDL para FPGAs estudiando el consumo de área y tiempo de las operaciones comparando los resultados entre sí y con los obtenidos por otros autores. [ABSTRACT]Finite field arithmetic has received much attention due to its importance in cryptography, error control coding and digital signal processing. A large portion of time from the routines of the cryptographies algorithms is used in the calculation of arithmetic operations on finite fields. Systems using this arithmetic must be faster because of performance required in current communication systems. Addition in GF(2^m) is bit independent XOR operation, it can be implemented in fast and inexpensive ways. Nevertheless other operations are much more complex and expensive. The efficiency of the hardware implementations is measured in terms of the numbers of gates (XOR and AND) and of the total gate delay of the circuit. The aim of this document is to make a comparative study of different arithmetic circuits over GF(2^m), NIST and SECG recommended fields will be used. Due to multiplication is one of the most complex and important operation in finite field arithmetic, different implementations will be treated, parallel and serial along with digit-serial algorithms. To perform other operations, also inversion and square algorithms over GF(2^m) have been discussed. VHDL implementations of these algorithms for FPGAs have been realized to study time and area consumption and to compare the result each other and with other authors'results

A new approach in building parallel finite field multipliers

A new method for building bit-parallel polynomial basis finite field multipliers is proposed in this thesis. Among the different approaches to build such multipliers, Mastrovito multipliers based on a trinomial, an all-one-polynomial, or an equally-spacedpolynomial have the lowest complexities. The next best in this category is a conventional multiplier based on a pentanomial. Any newly presented method should have complexity results which are at least better than those of a pentanomial based multiplier. By applying our method to certain classes of finite fields we have gained a space complexity as n2 + H - 4 and a time complexity as TA + ([ log2(n-l) ]+3)rx which are better than the lowest space and time complexities of a pentanomial based multiplier found in literature. Therefore this multiplier can serve as an alternative in those finite fields in which no trinomial, all-one-polynomial or equally-spaced-polynomial exists

Novel Single and Hybrid Finite Field Multipliers over GF(2m) for Emerging Cryptographic Systems

With the rapid development of economic and technical progress, designers and users of various kinds of ICs and emerging embedded systems like body-embedded chips and wearable devices are increasingly facing security issues. All of these demands from customers push the cryptographic systems to be faster, more efficient, more reliable and safer. On the other hand, multiplier over GF(2m) as the most important part of these emerging cryptographic systems, is expected to be high-throughput, low-complexity, and low-latency. Fortunately, very large scale integration (VLSI) digital signal processing techniques offer great facilities to design efficient multipliers over GF(2m). This dissertation focuses on designing novel VLSI implementation of high-throughput low-latency and low-complexity single and hybrid finite field multipliers over GF(2m) for emerging cryptographic systems. Low-latency (latency can be chosen without any restriction) high-speed pentanomial basis multipliers are presented. For the first time, the dissertation also develops three high-throughput digit-serial multipliers based on pentanomials. Then a novel realization of digit-level implementation of multipliers based on redundant basis is introduced. Finally, single and hybrid reordered normal basis bit-level and digit-level high-throughput multipliers are presented. To the authors knowledge, this is the first time ever reported on multipliers with multiple throughput rate choices. All the proposed designs are simple and modular, therefore suitable for VLSI implementation for various emerging cryptographic systems

Low Complexity Finite Field Multiplier for a New Class of Fields

Finite fields is considered as backbone of many branches in number theory, coding theory, cryptography, combinatorial designs, sequences, error-control codes, and algebraic geometry. Recently, there has been considerable attention over finite field arithmetic operations, specifically on more efficient algorithms in multiplications. Multiplication is extensively utilized in almost all branches of finite fields mentioned above. Utilizing finite field provides an advantage in designing hardware implementation since the ground field operations could be readily converted to VLSI design architecture. Moreover, due to importance and extensive usage of finite field arithmetic in cryptography, there is an obvious need for better and more efficient approach in implementation of software and/or hardware using different architectures in finite fields. This project is intended to utilize a newly found class of finite fields in conjunction with the Mastrovito algorithm to compute the polynomial multiplication more efficiently

Efficient Bit-parallel Multiplication with Subquadratic Space Complexity in Binary Extension Field

Bit-parallel multiplication in GF(2^n) with subquadratic space complexity has been explored in recent years due to its lower area cost compared with traditional parallel multiplications. Based on \u27divide and conquer\u27 technique, several algorithms have been proposed to build subquadratic space complexity multipliers. Among them, Karatsuba algorithm and its generalizations are most often used to construct multiplication architectures with significantly improved efficiency. However, recursively using one type of Karatsuba formula may not result in an optimal structure for many finite fields. It has been shown that improvements on multiplier complexity can be achieved by using a combination of several methods. After completion of a detailed study of existing subquadratic multipliers, this thesis has proposed a new algorithm to find the best combination of selected methods through comprehensive search for constructing polynomial multiplication over GF(2^n). Using this algorithm, ameliorated architectures with shortened critical path or reduced gates cost will be obtained for the given value of n, where n is in the range of [126, 600] reflecting the key size for current cryptographic applications. With different input constraints the proposed algorithm can also yield subquadratic space multiplier architectures optimized for trade-offs between space and time. Optimized multiplication architectures over NIST recommended fields generated from the proposed algorithm are presented and analyzed in detail. Compared with existing works with subquadratic space complexity, the proposed architectures are highly modular and have improved efficiency on space or time complexity. Finally generalization of the proposed algorithm to be suitable for much larger size of fields discussed

LFSR-based bit-serial GF(^2m) multipliers using irreducible trinomials

In this article, a new architecture of bit-serial polynomial basis (PB) multipliers over the binary extension field GF(^2m) generated by irreducible trinomials is presented. Bit-serial GF(^2m) PB multiplication offers a performance/area trade-off that is very useful in resource constrained applications. The architecture here proposed is based on LFSR (Linear-Feedback Shift Register) and can perform a multiplication in m clock cycles with a constant propagation delay of T_A + T_X. These values match the best time results found in the literature for bit-serial PB multipliers with a slight reduction of the space complexity. Furthermore, the proposed architecture can perform the multiplication of two operands for t different finite fields GF(^2m) generated by t irreducible trinomials simultaneously in m clock cycles with the inclusion of t(m - 1) flipflops and tm XOR gates