The xkcd is bad advice. It mentions 1000 guesses per second. In reality GPU crackers can do 100,000,000,000 guesses per second. https://hashcat.net/oclhashcat/

The xkcd is bad advice. It mentions 1000 guesses per second. In reality GPU crackers can do 100,000,000,000 guesses per second. https://hashcat.net/oclhashcat/ https://hashcat.net/oclhashcat/ You need to add another 2-3 words.