Abstract or Summary:
Users have to deal with the wide diversity of password requirements when creating passwords for their user accounts at Internet services. In this talk, I present the first investigation of password requirements on a global scale by analyzing 185,696 services. Second, I present a security analysis of the requirements with respect to offline brute-force attacks. Third, I present an optimal password-composition rule for password generators to cope with the wide diversity of password requirements. Altogether, the password-composition rule leads to secure passwords, a better user experience, and finally helps users to create proper passwords for their user accounts.

PasswordResearch.com Note: Video of presentation: https://www.youtube.com/watch?v=AIGBMcP_deI