Security and Usability of a Personalized User Authentication Paradigm: Insights from a Longitudinal Study with Three Healthcare Organizations - Constantinides, Argyris; Belk, Marios; Fidas, Christos; Beumers, Roy; Vidal, David; Huang, Wanting; Bowles, Juliana; Webber, Thais; Silvina, Agastya; Pitsillides, Andreas (ACM Transactions on Computing for Healthcare, 2023)