Quantifying Shannon's Work Function for Cryptanalytic Attacks

Attacks on cryptographic systems are limited by the available computational resources. A theoretical understanding of these resource limitations is needed to evaluate the security of cryptographic primitives and procedures. This study uses an Attacker versus Environment game formalism based on computability logic to quantify Shannon's work function and evaluate resource use in cryptanalysis. A simple cost function is defined which allows to quantify a wide range of theoretical and real computational resources. With this approach the use of custom hardware, e.g., FPGA boards, in cryptanalysis can be analyzed. Applied to real cryptanalytic problems, it raises, for instance, the expectation that the computer time needed to break some simple 90 bit strong cryptographic primitives might theoretically be less than two years.Comment: 19 page

ESTABLISHED WAYS TO ATTACK EVEN THE BEST ENCRYPTION ALGORITHM

Which solution is the best – public key or private key encryption? This question cannot have a very rigorous, logical and definitive answer, so that the matter be forever settled :). The question supposes that the two methods could be compared on completely the same indicators – well, from my point of view, the comparison is not very relevant. Encryption specialists have demonstrated that the sizes of public key encrypted messages are much bigger than the encrypted message using private key algorithms. From this point of view, we can say that private key algorithms are more efficient than their newer counterparts. Looking at the issue through the eyeglass of the security level, the public key encryption have a great advantage of the private key variants, their level of protection, in the most pessimistic scenarios, being at least 35 time higher. As a general rule, each type of algorithm has managed to find its own market niche where could be applicable as a best solution and be more efficient than the other encryption model.Encryption, decryption, key, cryptanalysis, brute-force, linear, differential, algebra

Secret Key Cryptography Using Graphics Cards

One frequently cited reason for the lack of wide deployment of cryptographic protocols is the (perceived) poor performance of the algorithms they employ and their impact on the rest of the system. Although high-performance dedicated cryptographic accelerator cards have been commercially available for some time, market penetration remains low. We take a different approach, seeking to exploit {\it existing system resources,} such as Graphics Processing Units (GPUs) to accelerate cryptographic processing. We exploit the ability for GPUs to simultaneously process large quantities of pixels to offload cryptographic processing from the main processor. We demonstrate the use of GPUs for stream ciphers, which can achieve 75\% the performance of a fast CPU. We also investigate the use of GPUs for block ciphers, discuss operations that make certain ciphers unsuitable for use with a GPU, and compare the performance of an OpenGL-based implementation of AES with implementations utilizing general CPUs. In addition to offloading system resources, the ability to perform encryption and decryption within the GPU has potential applications in image processing by limiting exposure of the plaintext to within the GPU

Encrypting video and image streams using OpenCL code on- demand

La cantidad de información multimedia que se transmite a través de la web es muy alta y continua incrementándose. Generalmente, este tipo de datos no se los protege correctamente, dado que los usuarios no aprecian la cantidad de información que las imágenes y videos pueden contener. En este trabajo, presentamos una arquitectura para manejar de manera segura, canales de transmisión multimedia. La idea es encriptar o codificar imágenes y videos de una forma eficiente y dinámica. Al mismo tiempo, estos datos pueden ser mejorados aplicando un procesamiento en tiempo real. Lo novedoso de esta propuesta es la utilización en tiempo real de código bajo-demanda en paralelo escrito en OpenCL. Los algoritmos y estructura de datos son conocidos por los participantes de la comunicación, solo cuando esta comienza, lo que supone incrementa la robustez frente a posibles ataques. En el trabajo desarrollamos una descripción completa de la propuesta y varias pruebas de rendimiento con diferentes algoritmos.The amount of multimedia information transmitted through the web is very high and increasing. Generally, this kind of data is not correctly protected, since users do not appreciate the amount of information that images and videos may contain. In this work, we present architecture for managing safely multimedia transmission channels. The idea is to encrypt or encode images and videos in an efficient and dynamic way. At the same time, these media could be enhanced applying a real-time image process. The main novelty of the proposal is the application of on-demand parallel code written in OpenCL. The algorithms and data structure are known by the parties only at communication time, what we suppose increases the robustness against possible attacks. We conducted a complete description of the proposal and several performance tests with different known algorithms.Fil: D'amato, Juan Pablo. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Grupo de Plasmas Densos Magnetizados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Venere, Marcelo Javier. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Grupo de Plasmas Densos Magnetizados; Argentina. Comisión Nacional de Energía Atómica; Argentin

Fast, parallel and secure cryptography algorithm using Lorenz's attractor

A novel cryptography method based on the Lorenz's attractor chaotic system is presented. The proposed algorithm is secure and fast, making it practical for general use. We introduce the chaotic operation mode, which provides an interaction among the password, message and a chaotic system. It ensures that the algorithm yields a secure codification, even if the nature of the chaotic system is known. The algorithm has been implemented in two versions: one sequential and slow and the other, parallel and fast. Our algorithm assures the integrity of the ciphertext (we know if it has been altered, which is not assured by traditional algorithms) and consequently its authenticity. Numerical experiments are presented, discussed and show the behavior of the method in terms of security and performance. The fast version of the algorithm has a performance comparable to AES, a popular cryptography program used commercially nowadays, but it is more secure, which makes it immediately suitable for general purpose cryptography applications. An internet page has been set up, which enables the readers to test the algorithm and also to try to break into the cipher in

Accelerating NTRUEncrypt for in-browser cryptography utilising graphical processing units and WebGL

One of the challenges encryption faces is it is computationally intensive and therefore slow, it is vital to find faster methods to accelerate modern encryption algorithms to keep performance high whilst also preserving information security. Users often do not want to wait for applications to become responsive, applications on limited devices such as mobiles often compromise security in order to keep execution times quick. Often they use algorithms and key sizes which are not considered cryptographically secure in order to maintain a smooth user experience. Emerging approaches have begun using a devices Graphics Processing Unit (GPU) to offload some of the computational burden from the Central Processing Unit (CPU) in an effort to parallelize and accelerate the encryption algorithms. Programming for a GPU often involves the use of CUDA or OpenCL programming, however these approaches are platform dependant. This research focuses on utilizing a GPU to perform in-browser cryptography using WebGL and JavaScript. This allows any GPU-enabled device capable of launching an OpenGL compatible browser to perform GPU accelerated cryptography. A GPU based implementation of the NTRUEncrypt algorithm was created and tested against a CPU based version on a range of hardware devices with results, challenges and limitations discussed