A utilização do algoritmo quântico de busca em problemas da teoria da informação.

Abstract

This work presents two results related to Quantum Search Algorithm (Grover’s Algorithm) application in Information Theory problems. The first one aims to test the quality of a Linear Block Code, given that they have an important characteristic known as the minimum distance (d) among its composing words. The presented solution uses the Quantum Counting Algorithm to improve d’s calculation since the classical algorithms are intractable. Therefore, such distance can be used as a comparative parameter between different codes. The second studied problem is called Quantum Attack to Blum-Micali’s Pseudo-random Generator. Such generators are used at physical systems simulations and criptography, replacing really random numbers generators that are difficult to implement. The Grover’s Algorithm is used here to break the number generation process’ security