Influence of Mobile Devices on Password Composition and Authentication Performance Paper by: Emanuel von Zezschwitz, University of Munich, Germany Alexander De Luca, University of Munich, Germany Heinrich Hussmann, University of Munich, Germany

Pre-study assessing password performance

Independent variables  3 devices  Smartphone (Apple iPhone 5)  Tablet (Apple iPad 4 10”)  PC (Windows PC with 24” display and Cherry JK-0100DE keyboard)  3 password categories  Dictionary (ex. casanova)  Internet (ex. Yasana75)  Random (ex.

Procedure  Training: enter short text, no logging  Typing speed: enter text (different for each device)  Authentication: enter 4 password of each category  Repeat until all 3 devices had been tested Participants  24 experienced users  20 males; 4 females  Average age of 25

Results  Typing speed  Significantly influenced by the device  Smartphone slowest, PC fastest  Slower when string complexity increases  Error rate  Significantly influenced by the device  Smartphone is error prone

Large scale study choice and perception

Procedure  Password creation task asked to select a password for an imaginary service they would frequently use on the current device Participants  149 tablet users; 149 PC users; 152 smartphone users  238 males; 212 females  Average age of 31 years

Results  Password  Significantly influenced by the device  Smartphone shortest passwords, PC longest passwords  Tablet and smartphone use fewer upper case letters  Errors  Significantly influenced by the device  50% of all errors occurred on smartphones

Conclusion

 Mobile devices have significant impact on alphanumeric passwords  Slower input  More errors  Users opt for easy and fast to enter passwords  Limiting factors of password security  Used to be memorability  now it is input effort  Should provide adjusted authentication methods