I'm looking for a study or a research on how password policy affects signups. I'm sure there must be something available, but I'm unable to find it.
So one of my client wants me to implement a password policy. You know, your password must contain a special character, one upper case, lower case types. He is being very full on about it.
I recommended suggesting the password strength (like how Google does) instead of a hard and strong password rule, but it would be nice to cite some studies.