Diceware builds a passphrase from dice and a word list, so the randomness is the physical throw, not a program you have to trust. Arnold Reinhold published the method. The EFF long wordlist is the variant most people should use now, because the words are clearer. Five or six words from a 7,776-word list is a serious secret if the throws are real and you do not “improve” them.
Humans ruin it by picking favorite words, rerolling “ugly” results, or writing the list on a sticky note on the laptop. Diceware is for the few passwords you must memorize: a manager’s master passphrase, a disk encryption password. Everything else should be random and stored. Do not invent your own shorter list.
Use it for master secrets. The EFF list is at eff.org/dice.
Roll Diceware with real dice or a method that is actually random, not a song you like. Five words is a baseline. Six if the secret guards other secrets. The EFF list avoids confusing words. Write the result on paper once, put it in the password manager as the master, and do not also store it in a cloud note. If you can remember it without paper, it might be too patterned. That is allowed for a master password you type daily. It is not allowed to be a quote.
