TY  - CHAP
U1  - Konferenzveröffentlichung
A1  - Wiefling, Stephan
A1  - Dürmuth, Markus
A1  - Lo Iacono, Luigi
T1  - What's in Score for Website Users: A Data-Driven Long-Term Study on Risk-Based Authentication Characteristics
T2  - Borisov, Diaz (Eds.): Financial Cryptography and Data Security (FC '21). 25th International Conference, FC 2021, Virtual Event, March 1–5, 2021, Revised Selected Papers, Part II. Lecture Notes in Computer Science, vol 12675
N2  - Risk-based authentication (RBA) aims to strengthen password-based authentication rather than replacing it. RBA does this by monitoring and recording additional features during the login process. If feature values at login time differ significantly from those observed before, RBA requests an additional proof of identification. Although RBA is recommended in the NIST digital identity guidelines, it has so far been used almost exclusively by major online services. This is partly due to a lack of open knowledge and implementations that would allow any service provider to roll out RBA protection to its users. To close this gap, we provide a first in-depth analysis of RBA characteristics in a practical deployment. We observed N=780 users with 247 unique features on a real-world online service for over 1.8 years. Based on our collected data set, we provide (i) a behavior analysis of two RBA implementations that were apparently used by major online services in the wild, (ii) a benchmark of the features to extract a subset that is most suitable for RBA use, (iii) a new feature that has not been used in RBA before, and (iv) factors which have a significant effect on RBA performance. Our results show that RBA needs to be carefully tailored to each online service, as even small configuration adjustments can greatly impact RBA's security and usability properties. We provide insights on the selection of features, their weightings, and the risk classification in order to benefit from RBA after a minimum number of login attempts.
KW  - Big Data Analysis
KW  - Usable Security
KW  - Risk-based Authentication (RBA)
KW  - Authentication features
UN  - https://nbn-resolving.org/urn:nbn:de:hbz:1044-opus-59566
SN  - 978-3-662-64330-3
SB  - 978-3-662-64330-3
U6  - https://doi.org/10.1007/978-3-662-64331-0_19
DO  - https://doi.org/10.1007/978-3-662-64331-0_19
SP  - 361
EP  - 381
PB  - Springer
CY  - Berlin, Heidelberg
ER  -