Understanding EFF-style passphrases

A passphrase combines independently selected random words. It is not a quotation, a sentence you invent, or a list of your favorite things.

How the word selection works

The prototype uses the full 7,776-word EFF Large Wordlist. Each word is selected independently and uniformly using cryptographic random bytes with rejection sampling. Repeated words are allowed: excluding them would change the distribution. Six independently chosen words provide about 77.5 bits of selection entropy; twelve provide about 155 bits. This describes the random selection, not a guarantee about a person or device.

Keep the randomness

A fixed hyphen separator helps distinguish words but contributes no extra entropy. Replacing words, choosing a familiar phrase, or repeatedly regenerating until a phrase feels meaningful can reduce the assumptions behind an entropy estimate. Store a unique passphrase per account in a trusted password manager rather than reusing it.

Physical dice are another option

The EFF list maps five six-sided dice rolls to a word. Repeating that process independently for each word is an offline alternative when you have fair dice and can protect the result. The browser prototype uses a cryptographic generator instead of simulating physical dice with ordinary random numbers.

Availability and attribution

The separate sensitive workspace is gated until its dedicated origin and absence of injected scripts are verified. This introduction contains no secret-input form. The wordlist is credited to the Electronic Frontier Foundation under CC BY 3.0 US; use of the list does not imply endorsement. Read the original method at https://www.eff.org/dice.

Tools do not remove your applicable legal rights or our responsibilities under applicable law. No security or liability immunity is promised.