3 ms·
It has occurred to me recently that 12 random words from a 2000 word dictionary will give you 132 bits on entropy. More that you will ever need. There's a numb
by DenisM 11y ago
It has occurred to me recently that 12 random words from a 2000 word dictionary will give you 132 bits on entropy. More that you will ever need.
There's a number of advantages to this scheme:
- It's easy to write down and put in a safe.
- No funny characters required.
- Not case-sensitive.
- If a user makes a spelling error, we can correct it for him without any compromise in security.
- Guaranteed to be free from offensive words, unlike a randomly generated password.
- People are using words anyways, misspelled if necessary, whether we like it or not.
We can also make it even more user-friendly by carefully degrading security, such as trying common word substitutions for the forgetful users, or doing some kind of middle-ground "remember me" that does not let you straight in, but only demands first three words (to keep the family members at bay). Like I said, this required careful calculations as to how much security is sacrificed when we do that.
- oniony 11y agoThis was made clear many moons ago by the now famous xkcd strip https://www.xkcd.com/936/ https://www.xkcd.com/936/
- DenisM 11y agoMy innovation :) is to prevent users from selecting their own words, so that we can actually guarantee the entropy required. Otherwise a Markov chain will tear it to pieces.
- cuckcuckspruce 11y agoYou mean like Diceware[1], which has been around since at least 2000? [1] http://world.std.com/~reinhold/diceware.html http://world.std.com/~reinhold/diceware.html
- DenisM 11y agoGood stuff. All we need now is to marry it with a password manager so that it generates random passwords based on this one passphrase and then autofills the web forms for you.
- falcolas 11y agoAlso done frequently in the past, see: http://world.std.com/~reinhold/diceware.html http://world.std.com/~reinhold/diceware.html Some intrepid child got internet famous recently for making some money by doing this for you.
- munificent 11y agoAlas, many many many sites have inanely short password length limitations.