Ensure your customers are entering a strong password.

You can easily modify the strength level from the opencart admin extension. E.g: Password must:
Be at least 8 character(s)
Mixed upper/lower alphabetic characters (A-Z or a-z)
At least 1 number(s)
At least one special character: /['^£$*()}{@#~?<>,.|=_+!-]"[/list]

Includes password policy validation for:
Customer Register
Customer Password Reset
Customer Edit Password
Affiliate
Admin Password

Install easily using Opencart's Extension Installer.