(FUVEST - 2013- 2 fase)Two decades ago only spies

(FUVEST - 2013 - 2ª fase) 

Two decades ago only spies and systems administrators had to worry about passwords. But today you have to enter one even to do humdrum things like turning on your computer, downloading an album or buying a book online. No wonder many people use a single, simple password for everything. Analysis of password databases, often stolen from websites (something that happens with disturbing frequency), shows that the most common choices include “password”, “123456” and “abc123”. But using these, or any word that appears in a dictionary, is insecure. Even changing some letters to numbers ( “e” to “3”, “i” to “1” and so forth) does little to reduce the vulnerability of such passwords to an automated “dictionary attack”, because these substitutions are so common. The fundamental problem is that secure passwords tend to be hard to remember, and memorable passwords tend to be insecure.

The Economist. March 24th 2012. Adapted.

Com base no texto, responda em português:

a) Por que a criação de senhas por usuários da internet pode lhes trazer problemas?

b) A troca de algumas letras por números, nas senhas, é uma boa medida? Justifique sua resposta.