Generate a passphrase
Several French words drawn at random beat a short password on both counts: harder to break, and far easier to remember. This is the dice method, without the dice.
Holds for everyday accounts. For your email or a password manager, add a word or two.
Each word is drawn at random from a list of 512, which is exactly 9 bits per word. Capitalisation and the added digit bring almost nothing: an attacker tries them first.
The draw happens in your browser with its cryptographic random generator. Nothing is sent, nothing is stored.
Why is a passphrase stronger than X7#kp2 ?
Because strength comes from length, not from typographic contortions. X7#kp2 offers six characters out of ninety-five possible ones, which a machine exhausts in seconds. Eight words drawn from a list of 512 offer 72 bits: the same machine would spend decades on it. And that one, you actually remember.
What does the dice method mean?
It comes from Diceware, a method invented in 1995: you roll physical dice, and the result points at a word in a numbered list. The point is not the list, it is the drawing. A word you choose yourself is worth almost nothing, because you would pick it the way everyone does. The same word drawn at random is worth its full value. Here the dice are replaced by your browser's cryptographic random generator.
How many words should you use?
Seven words, sixty-three bits, hold for several weeks against a fast-hashed stolen database. Eight words, the default here, bring that to seventy-two bits and push cracking into decades. Below seven, count in hours or days: acceptable for a forum of no consequence, not for your email or a password manager's master password, which unlock everything else. The tool shows the entropy in bits and the time to break it, so the choice is not a matter of belief.
What not to do with it
- Do not add a word of your own to make it feel more personal: it destroys the randomness that gives it its value.
- Do not reuse it on several sites, whatever its strength: a leak on one site would carry it to the others.
- Do not draw it on someone else's computer, and prefer a manager to store it rather than a note.
Frequently asked questions
Is the passphrase sent anywhere?
No. The draw happens in your browser, using its cryptographic random generator. Nothing is sent to our server, nothing is stored, and no passphrase is ever logged. You can cut your connection: the tool still works.
Is the word list public? Does that weaken the passphrase?
No, and this is the counter-intuitive part. The list is public and holds 512 words. The strength comes from the drawing, not from secrecy: an attacker who knows the list still has to try every combination, which is exactly what the announced entropy measures.
Why exactly nine bits per word?
Because the list holds exactly 512 words, and 512 is two to the power of 9. Every drawn word therefore adds precisely 9 bits, with no rounding in what is claimed.
Does adding a capital and a digit make it much stronger?
Almost not at all, and the tool says so. Capitalising the first letter and appending a digit are the first two transformations a cracking tool tries. They add barely more than four bits, where one extra word adds nine.
Can I change a word I do not like?
You can, but every substitution you make yourself lowers the real strength, because your choice is predictable in a way the draw is not. Draw again instead.
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