@inproceedings{WieflingDuermuthLoIacono2020,
  author    = {Stephan Wiefling and Markus D{\"u}rmuth and Luigi Lo Iacono},
  title     = {More Than Just Good Passwords? A Study on Usability and Security Perceptions of Risk-based Authentication},
  series = {36th Annual Computer Security Applications Conference (ACSAC '20). December 07-11, 2020},
  publisher = {ACM},
  isbn      = {978-1-4503-8858-0},
  doi       = {10.1145/3427228.3427243},
  url       = {https://nbn-resolving.org/urn:nbn:de:hbz:1044-opus-50707},
  pages     = {203 -- 218},
  year      = {2020},
  abstract  = {Risk-based Authentication (RBA) is an adaptive security measure to strengthen password-based authentication. RBA monitors additional features during login, and when observed feature values differ significantly from previously seen ones, users have to provide additional authentication factors such as a verification code. RBA has the potential to offer more usable authentication, but the usability and the security perceptions of RBA are not studied well. We present the results of a between-group lab study (n=65) to evaluate usability and security perceptions of two RBA variants, one 2FA variant, and password-only authentication. Our study shows with significant results that RBA is considered to be more usable than the studied 2FA variants, while it is perceived as more secure than password-only authentication in general and comparably secure to 2FA in a variety of application types. We also observed RBA usability problems and provide recommendations for mitigation. Our contribution provides a first deeper understanding of the users' perception of RBA and helps to improve RBA implementations for a broader user acceptance.},
  language  = {en}
}