A Large-Scale Study of Web Password Habits

This paper reports the results of a large scale study of password use and password re-This paper reports the results of a large scale study of password use and password re-use habits. The study involved half a million users over a three month period. A client component on users' machines recorded a variety of password strength, usage and frequency metrics. This allows measuring or estimating such quantities as the average number of pass-words and average number of accounts each user has, how many passwords she types per day, how often passwords are shared among sites, and how often they are forgotten. The authors got extremely detailed data on password strength, the types and lengths of passwords chosen, and how they vary by site.habits. The study involved half a million users over a three month period. A client component on users' machines recorded a variety of password strength, usage and frequency metrics. This allows measuring or estimating such quantities as the average number of pass-words and average number of accounts each user has, how many passwords she types per day, how often passwords are shared among sites, and how often they are forgotten. The authors get extremely detailed data on password strength, the types and lengths of passwords chosen, and how they vary by site.