Improving Users' Passwords with DPAR: a Data-driven Password Recommendation System
Assaf Morag, Liron David, Eran Toch, Avishai Wool
TL;DR
DPAR addresses the ongoing challenge of helping users create strong, memorable passwords by recommending small, user-specific edits rather than generating entirely new passwords. It leverages PESrank, a data-driven strength model trained on a corpus of 905 million leaked passwords, to decompose a password into five dimensions and generate 676 candidate tweaks that balance similarity and security. Across two studies (n=317 memorability; n=441 strength/recall), DPAR increased password strength by about 34.8 bits on average and achieved a 36.6% verbatim adoption rate of recommendations, with recall unaffected relative to feedback-only approaches. The work demonstrates that actionable, per-password recommendations can boost security while maintaining usability, though interface design and privacy considerations warrant careful attention for real-world deployment.
Abstract
Passwords are the primary authentication method online, but even with password policies and meters, users still find it hard to create strong and memorable passwords. In this paper, we propose DPAR: a Data-driven PAssword Recommendation system based on a dataset of 905 million leaked passwords. DPAR generates password recommendations by analyzing the user's given password and suggesting specific tweaks that would make it stronger while still keeping it memorable and similar to the original password. We conducted two studies to evaluate our approach: verifying the memorability of generated passwords (n=317), and evaluating the strength and recall of DPAR recommendations against password meters (n=441). In a randomized experiment, we show that DPAR increased password strength by 34.8 bits on average and did not significantly affect the ability to recall their password. Furthermore, 36.6% of users accepted DPAR's recommendations verbatim. We discuss our findings and their implications for enhancing password management with recommendation systems.
