AES-CBC Software Execution Optimization

With the proliferation of high-speed wireless networking, the necessity for efficient, robust and secure encryption modes is ever increasing. But, cryptography is primarily a computationally intensive process. This paper investigates the performance and efficiency of IEEE 802.11i approved Advanced Encryption Standard (AES)-Rijndael ciphering/deciphering software in Cipher Block Chaining (CBC) mode. Simulations are used to analyse the speed, resource consumption and robustness of AES-CBC to investigate its viability for image encryption usage on common low power devices. The detailed results presented in this paper provide a basis for performance estimation of AES cryptosystems implemented on wireless devices. The use of optimized AES-CBC software implementation gives a superior encryption speed performance by 12 - 30%, but at the cost of twice more memory for code size.Comment: 8 pages, IEEE 200

Reconfigurable elliptic curve cryptography

Elliptic Curve Cryptosystems (ECC) have been proposed as an alternative to other established public key cryptosystems such as RSA (Rivest Shamir Adleman). ECC provide more security per bit than other known public key schemes based on the discrete logarithm problem. Smaller key sizes result in faster computations, lower power consumption and memory and bandwidth savings, thus making ECC a fast, flexible and cost-effective solution for providing security in constrained environments. Implementing ECC on reconfigurable platform combines the speed, security and concurrency of hardware along with the flexibility of the software approach. This work proposes a generic architecture for elliptic curve cryptosystem on a Field Programmable Gate Array (FPGA) that performs an elliptic curve scalar multiplication in 1.16milliseconds for GF (2163), which is considerably faster than most other documented implementations. One of the benefits of the proposed processor architecture is that it is easily reprogrammable to use different algorithms and is adaptable to any field order. Also through reconfiguration the arithmetic unit can be optimized for different area/speed requirements. The mathematics involved uses binary extension field of the form GF (2n) as the underlying field and polynomial basis for the representation of the elements in the field. A significant gain in performance is obtained by using projective coordinates for the points on the curve during the computation process

A comparison of different finite fields for elliptic curve cryptosystems

AbstractWe examine the relative efficiency of four methods for finite field representation in the context of elliptic curve cryptography (ECC). We conclude that a set of fields called the optimized extension fields (OEFs) give greater performance, even when used with affine coordinates, when compared against the type of fields recommended in the emerging ECC standards. Although this performance advantage is only marginal, and hence, there is probably no need to change the current standards to allow OEF fields in standards compliant implementations

NTRU software implementation for constrained devices

The NTRUEncrypt is a public-key cryptosystem based on the shortest vector problem. Its main characteristics are the low memory and computational requirements while providing a high security level. This document presents an implementation and optimization of the NTRU public-key cryptosys- tem for constrained devices. Speci cally the NTRU cryptosystem has been implemented on the ATMega128 and the ATMega163 microcontrollers. This has turned in a major e ort in order to reduce the consumption of memory and op- timize the computational resources. The di erent resulting optimizations have been compared and evaluated throught the AVR Studio 4 [1]. The nal outcome has also been compared with other published public-key cryptosystems as RSA or ECC showing the great performance NTRUEncrypt is able to deliver at a surprising very low cost

Performance Analysis of Rainbow on ARM Cortex-M4

The risk posed by a fully operational quantum computer has anticipated a revolution in the way to approach the level of security provided by a cryptographic algorithm. Public keybased solutions such as RSA or ECC will be easily broken once we enter the post-quantum era. Multivariate quadratic cryptosystems are a promising candidate for the need of quantum resistant digital signature schemes. In order to estimate if these approach will someday be able to replace current standards, it is necessary to determine how ef?ciently can they operate on diverse platforms and at which level of security can they do it. This aspects are particularly relevant for reduced size devices with restricted energy, memory or computational power. In this work, a theoretical description of the so-called Rainbow multivariate signature algorithm is given, which is later implemented on a memory-constrained environment. An optimization approach is proposed in order to improve the ef?ciency of the scheme, in terms of message signature and veri?cation speed. A performance comparison is also presented between various state-of-the-art post-quantum signature cryptosystems and the optimized instances of Rainbow, in order to study its characteristics from a wider perspective.El riesgo que supone un futuro ordenador cuántico con suficientes recursos computacionales ha anticipado una revolución en la manera de enfocar la seguridad de la información. Varias técnicas de clave pública empleados tradicionalmente, como el RSA o el ECC resultarán totalmente desprotegidos en cuanto la sociedad moderna entre en la era cuántica. Algoritmos de encriptación basados ??en ecuaciones polinómicas multivariable son actualmente un potencial candidato para producir firmas digitales suficientemente robustas contra sistemas de computación cuántica. Para evaluar las capacidades de esta técnica y estudiar la posibilidad de sustituir los sistemas tradicionales de encriptación en un futuro próximo, es necesario cuantificar por un lado la eficiencia a la que pueden operar en diferentes plataformas y por otro lado el nivel de seguridad que pueden llegar a ofrecer. Estos aspectos son especialmente clave en dispositivos de tamaño reducido con restricciones sobre el consumo de energía, la cantidad de memoria disponible o la potencia computacional. En este trabajo, se da una descripción teórica del algoritmo Rainbow, basado en ecuaciones polinómicas multivariable, el cual es posteriormente implementado sobre un sistema limitado en memoria. Adicionalmente se propone una modificación en el algoritmo original, con el fin de de reducir el tiempo de ejecución de firma y verificación de mensajes. Finalmente, se presenta una comparación de rendimiento entre diversas técnicas criptográficas dedicadas a firma digital y las instancias que se implementan en esta disertación, para así analizar las características de los sistemas de encriptación basados ??en ecuaciones polinómicas multivariable desde una perspectiva más amplia.El risc que suposa un futur ordinador quàntic amb suficients recursos computacionals ha anticipat una revolució en la manera d'enfocar la seguretat de la informació. Diverses tècniques de clau pública emprats tradicionalment, com l'RSA o l'ECC esdevindràn totalment vulnerables tant bon punt la societat moderna entri en l'era quàntica. Sistemes d'encriptació basats en equacions polinòmiques multivariable són actualment un potencial candidat per produïr firmes digitals suficientment robustes contra sistemes de computació quàntica. Per avaluar les capacitats d'aquesta tècnica i estudiar la possibilitat de substituir els sistemes tradicionals d'encriptació en un futur pròxim, és necessari quantificar d'una banda la eficiència a la que poden operar en diferents plataformes i d'altra banda el nivell de seguretat que poden arribar a oferir. Aquests aspectes són especialment clau en dispositius de mida reduïda amb restriccions sobre el consum d'energia, la quantitat de memòria disponible o la potència computacional. En aquest treball, es dóna una descripció teòrica de l'algoritme Rainbow, basat en equacions polinòmiques multivariable, el qual és posteriorment implementat sobre un sistema limitat en memòria. Adicionalment es proposa una modificació a l'algoritme original, per tal de de reduïr el temps d'execució de firma i verificació de missatges. Finalment, es presenta una comparació de rendiment entre diverses tècniques criptogràfiques dedicades a firma digital i les instàncies que s'implementen en aquesta dissertació, per així analitzar les característiques dels sistemes d'encriptació basats en equacions polinòmiques multivariable des d'una perspectiva més amplia

Elliptic curve cryptosystem over optimal extension fields for computationally constrained devices

Data security will play a central role in the design of future IT systems. The PC has been a major driver of the digital economy. Recently, there has been a shift towards IT applications realized as embedded systems, because they have proved to be good solutions for many applications, especially those which require data processing in real time. Examples include security for wireless phones, wireless computing, pay-TV, and copy protection schemes for audio/video consumer products and digital cinemas. Most of these embedded applications will be wireless, which makes the communication channel vulnerable. The implementation of cryptographic systems presents several requirements and challenges. For example, the performance of algorithms is often crucial, and guaranteeing security is a formidable challenge. One needs encryption algorithms to run at the transmission rates of the communication links at speeds that are achieved through custom hardware devices. Public-key cryptosystems such as RSA, DSA and DSS have traditionally been used to accomplish secure communication via insecure channels. Elliptic curves are the basis for a relatively new class of public-key schemes. It is predicted that elliptic curve cryptosystems (ECCs) will replace many existing schemes in the near future. The main reason for the attractiveness of ECC is the fact that significantly smaller parameters can be used in ECC than in other competitive system, but with equivalent levels of security. The benefits of having smaller key size include faster computations, and reduction in processing power, storage space and bandwidth. This makes ECC ideal for constrained environments where resources such as power, processing time and memory are limited. The implementation of ECC requires several choices, such as the type of the underlying finite field, algorithms for implementing the finite field arithmetic, the type of the elliptic curve, algorithms for implementing the elliptic curve group operation, and elliptic curve protocols. Many of these selections may have a major impact on overall performance. In this dissertation a finite field from a special class called the Optimal Extension Field (OEF) is chosen as the underlying finite field of implementing ECC. OEFs utilize the fast integer arithmetic available on modern microcontrollers to produce very efficient results without resorting to multiprecision operations or arithmetic using polynomials of large degree. This dissertation discusses the theoretical and implementation issues associated with the development of this finite field in a low end embedded system. It also presents various improvement techniques for OEF arithmetic. The main objectives of this dissertation are to --Implement the functions required to perform the finite field arithmetic operations. -- Implement the functions required to generate an elliptic curve and to embed data on that elliptic curve. -- Implement the functions required to perform the elliptic curve group operation. All of these functions constitute a library that could be used to implement any elliptic curve cryptosystem. In this dissertation this library is implemented in an 8-bit AVR Atmel microcontroller.Dissertation (MEng (Computer Engineering))--University of Pretoria, 2006.Electrical, Electronic and Computer Engineeringunrestricte

Aspects of hardware methodologies for the NTRU public-key cryptosystem

Cryptographic algorithms which take into account requirements for varying levels of security and reduced power consumption in embedded devices are now receiving additional attention. The NTRUEncrypt algorithm has been shown to provide certain advantages when designing low power and resource constrained systems, while still providing comparable security levels to higher complexity algorithms. The research presented in this thesis starts with an examination of the general NTRUEncrypt system, followed by a more practical examination with respect to the IEEE 1363.1 draft standard. In contrast to previous research, the focus is shifted away from specific optimizations but rather provides a study of many of the recommended practices and suggested optimizations with particular emphasis on polynomial arithmetic and parameter selection. Various methods are examined for storing, inverting and multiplying polynomials used in the system. Recommendations for algorithm and parameter selection are made regarding implementation in software and hardware with respect to the resources available. Although the underlying mathematical principles have not been significantly questioned, stable recommended practices are still being developed for the NTRUEncrypt system. As a further complication, recommended optimizations have come from various researchers and have been split between hardware and software implementations. In this thesis, a generic VHDL model is presented, based on the IEEE 1363.1 draft standard, which is designed for adaptation to software or hardware implementation while providing flexibility for changes in recommended practices