MultiConvers

Password Length vs Complexity

On a random password, adding characters usually beats adding a punctuation rule to a short string.

Complexity rules still help when they stop you from using a dictionary word.

By Andreas Rosenberg

The trade-off in one sentence

If each character is chosen at random, a longer password with a modest character set outruns a short password that is forced to include uppercase, a digit and a symbol.

A concrete comparison

Suppose a generator can pick from 26 lowercase letters. Eight random letters give 26⁸ possibilities. Sixteen random letters give 26¹⁶ — far more, without adding a single !.

Now take an 8-character password that must include mixed case, a digit and a symbol. The extra symbols enlarge the set, but eight slots is still eight slots. People also satisfy those rules in predictable ways (Name2024!), which throws away the extra set size.

Where to spend effort
ChangeWhen it helps
Add length to a random passwordAlmost always, if you can store it
Add character types to a random passwordUseful; smaller effect than the same number of extra characters
Require a symbol on a human-chosen short wordStops the most obvious dictionary picks; easy to game

What complexity rules are for

Rules exist because people pick words. They are a blunt tool. They do not replace uniqueness or a manager. For how long to go when the password is random, see how long a password should be.

Generate a random string — length and character types together — with the MultiConvers password generator, then follow how to create a strong password.

FAQ

Should I turn symbols off in a generator?

Only if the site rejects them or you must type the password by hand. A slightly smaller set at the same length is a little weaker, not a disaster.

Why do sites still demand a symbol and a number?

Those rules try to block “password” and “letmein”. They do not make Summer2024! a good secret.

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