Exact model

Guess a six-word random passphrase

Probability:
4.52 × 10⁻²²%
Odds:
1 to (2.21 × 10²³)
dBan
−233.4 dBan

Six ordinary words can form a surprisingly difficult secret when they are chosen at random. One guess has to match every word in the right order.

Calculation

p = 1 / 7,776⁶ = 1 / 221,073,919,720,733,357,899,776

Assumptions

Each word is sampled independently and uniformly from 7,776 words. Order matters, words may repeat, and the probability covers one independent guess.

Sources

  1. EFF: Dice-Generated Passphrases
  2. EFF: new wordlists for random passphrases
  3. EFF Surveillance Self-Defense: creating strong passwords