An empirical study of touch-based authentication methods on smartwatches

TL;DR

This study evaluates touch-based authentication methods on smartwatches, revealing trade-offs between accuracy, speed, and security, and highlighting user preferences versus optimal security practices.

Contribution

It provides empirical insights into how different authentication methods, UI designs, and display sizes impact smartwatch security and usability, guiding future design improvements.

Findings

PIN is more accurate and secure than Pattern

Pattern authentication is faster than PIN

Square UIs are more secure but less accurate than Circular UIs

Abstract

The emergence of smartwatches poses new challenges to information security. Although there are mature touch-based authentication methods for smartphones, the effectiveness of using these methods on smartwatches is still unclear. We conducted a user study (n=16) to evaluate how authentication methods (PIN and Pattern), UIs (Square and Circular), and display sizes (38mm and 42mm) affect authentication accuracy, speed, and security. Circular UIs are tailored to smartwatches with fewer UI elements. Results show that 1) PIN is more accurate and secure than Pattern; 2) Pattern is much faster than PIN; 3) Square UIs are more secure but less accurate than Circular UIs; 4) display size does not affect accuracy or speed, but security; 5) Square PIN is the most secure method of all. The study also reveals a security concern that participants' favorite method is not the best in any of the measures. We finally discuss implications for future touch-based smartwatch authentication design.