How much more secure, mathematically, is a 6 digit password than a 4
digit, an 8 digit than a 4 digit, etc.? I mean, if a site says I can make
up a password of 4-10 characters, I am wondering if going beyond the 4
chars to 5,6,7,8,9,10 makes the password more secure in a linear or
exponential manner. I am finally learning to take passwords seriously,
making stronger, more randon, non-dictionary passwords. Just curious about
the mathematical relationship between password length and strength.