Stanford University (USA) have proven that if you use 4 words that are 21 in size or more is a very safe password, as long as the words are random.
| Password | Size | |
|---|---|---|
| orangeeaglekeyshoewalk | 22 | |
| widowsunshinewinterhat | 22 | |
| butterflyrainmonopoly | 21 | |
| wombatsailingneptunegod | 23 |