Apple Passwords’ generated strong password format

I'm glad someone is thinking about UX and ergonomics when it comes to passwords. Most people I interact with have by now realized that generating passwords is a good idea. But if you are already generating the password, please do not include special characters. I regularly use different keyboard layouts (sometimes it is not even clear which layout is active, like in the vSphere web console), and the fact that passwords are often not shown on the screen when typing them makes for terrible UX and causes frustration.

The usual advice about character classes is only for casual users who don't know what makes a secure password. Entropy is the deciding factor: Ten random lower case letters is much more secure than "Summer2024!", which satisfies most password rules and has more characters.

Personally I stick to lower case letters for things like my Netflix password or Wifi key, because typing with a TV remote can be a huge pain. To keep a similar entropy, just increase the length by one or two characters.

> The usual advice about character classes is only for casual users who don't know what makes a secure password.

Arguably, it was to make early rainbow tables less feasible.

> if you are already generating the password, please do not include special characters.

This would make your generator useless on most sites. Since it's not the generator making up this rule, it's the web site's password "complexity" requirements.

I do agree password strength tests should just measure bits of entropy and allow whatever's typed that's high enough.

I don’t believe it’s possible to estimate the amount of entropy in a password - it’s too short so then you have to evaluate it against a dictionary. That’s why things are moving to passkeys but NIST recommendations thankfully have finally been updated to stop recommending weird password rules.

An important distinction that often gets lost is that entropy is a property of a probability distribution. A system to generate passwords has entropy, one specific password does not.

It's possible to read "hunter2" from /dev/random.

To infer entropy from a single password, the best you can do is to see if it falls within the domain of some known, low-entropy systems. This works ok in practice, but is very far from perfect.