Diceware refers to a technique for generating strong yet easy-to-remember passphrases by rolling dice. The resulting password consists of a string of words randomly chosen from a predefined list.
Most of your passwords should be generated by and stored in your password manager. However, there are certain scenarios where you will need to frequently type in a password manually, such as the passphrase you use to secure your password manager itself or to unlock your device. In these situations, you need a passphrase that is both easy to remember and easy to type without sacrificing strength.
The diceware technique utilizes a large, predefined word list consisting of single words paired with numbers representing the results of dice rolls:
11111 abacus 11112 abdomen 11113 abdominal 11114 abide 11115 abiding 11116 ability 11121 ablaze 11122 able ... 66666 zoom
The above list excerpted from one of EFF’s word lists is designed for five six-sided dice (or five rolls of a single die). For as many words as you want in your passphrase, roll the dice and find the word corresponding to the result of the roll. You can include a character of your choice, such as a space, to put between each word in your passphrase:
voucher tacking preamble yonder accustom catchable isotope cubbyhole
The resulting strength of the passphrase depends on the number of words you include and the size of the original word list. As a rule of thumb, we recommend choosing a minimum of six words from a word list of this size. You can find word lists and more details on password strength below: