Generate a 4 word password from words of size 3-8 characters, with frequencies in the 30th-60th percentile. This range gives a nice set of uncommon but not completely alien words. $ chbs generate --verbose -W 3..8 -P 30..60 Corpus size: 6396 candidate words of 33075 total Entropy: 48 bits (2^48 = 281474976710656) Years to guess at 1000 guesses/sec: 8926 magnate-thermal-sandbank-augur With the --verbose flag, the utility will calculate a time-to-guess based on a completely arbitrary 1000 guesses/sec. If you'd like a more secure password, either relax the various filtering rules (-W and -P), add more words to the password, or use a larger corpus. By default we use the American TV Shows & Scripts corpus taken from Wiktionary. Others provided: * Project Gutenberg 2005 corpus taken from Wiktionary. * 1 of every 7 of the top 60000 lemmas from wordfrequency.info (6900 actual lemmas after processing) See http://xkcd.com/936/ for the genesis of the idea. Data sources: http://en.wiktionary.org/wiki/Wiktionary:Frequency_lists http://wordfrequency.info/