Linear cryptanalysis of pseudorandom functions

Relatório de projeto de pesquisa.In this paper, we study linear relations propagating across block ciphers from the key input to the ciphertext (for a fixed plaintext block). This is a usual setting of a one-way function, used for instance in modes of operation such as KFB (key feedback). We instantiate the block cipher with the full 16-round DES and $s^2$-DES, 10-round LOKI91 and 24-round Khufu, for which linear relations with high bias are well known. Other interesting targets include the full 8.5-round IDEA and PES ciphers for which high bias linear relations exist under the assumption of weak keys. Consequences of these findings impact the security of modes of operation such as KFB and of pseudorandom number/bit generators. These analyses were possible due to the linear structure and the poor diffusion of the key schedule algorithms. These findings shall motivate carefull (re)design of current and future key schedule algorithms

O Contexto da Implantação do Acordo TRIPS

1. Introdução 2. Acordos e Convenções anteriores ao Trips 2.1 A Convenção de Paris para a Proteção da Propriedade Industrial 2.2 A Conferência de Berna para a Proteção das Obras Literárias e Artísticas 2.3 A Constituição da OMPI 2.4 O Acordo GATT - General Agreement on Tariffs and Trade 3. O contexto e os interesses explícitos e implícitos no Trips 3.1 Requisitos do Trips 4. Conclusão 5. Referência

A possibilidade de ação do Tribunal Penal Internacional em Uganda e na República Centro Africana: uma justiça que ameaça a paz?

O artigo é uma abordagem sobre a possibilidade de ação do Tribunal Penal Internacional em Uganda e na República Centro African

ACOUSTIC CAVITIES DESIGN PROCEDURES

Combustion instability is recognized as one of the major problems frequently faced by engineers during the development of either liquid or solid propellant rocket engines. The performance of the engine can be highly affected by these high frequencies instabilities, possibly leading the rocket to an explosion. The main goal while studying combustion chambers instability, either by means of baffles or acoustic absorbers, is to achieve the stability needed using the simplest possible manner. This paper has the purpose of studying combustion chambers instabilities, as well as the design of acoustic absorbers capable of reducing their eigenfrequencies. Damping systems act on the chamber eigenfrequency, which has to be, therefore, previously known

Knowledge Management and Analysis of Scientific Biotechnology Trends in Venezuela

This paper presents a study on knowledge management and analysis of scientific Biotechnology trends in Venezuela, providing an overview of the science profile as well as regional development and its relation to issues of topics covered by Biotechnology based on the analysis of scientific publications for the period of 1995 to 2010. The survey was accomplished in database ISI/Web of Science using 60 terms selected by experts in Biotechnology and 803 register has been organized. Scientific indicators were produced using data/ text mining tools. It was possible to find a greater number of scientific publications in areas such as Ecology and Health, showing a greater frequency in these terms: DNA, PCR and Biodiversity. Results pointed out The United States of America as the main foreign partner-country of scientific publications followed by Spain and France. It was possible to verify cooperation network with others Latin American countries: Brazil, Colombia and Chile