No that's not sane. As you say yourself it is a pain to implement and complex code is more prone to errors. It is far more easy to require a minimum length and

No that's not sane. As you say yourself it is a pain to implement and complex code is more prone to errors. It is far more easy to require a minimum length and choose a sane minimum, 8 is not. Also see this XKCD http://xkcd.com/936/ http://xkcd.com/936/ as an information theory refresher.