Secure Text Entry using a Virtual Radial Keyboard with Dynamically Resized Keys and Non-Intrusive Randomization

TL;DR

This paper presents a secure VR text entry method using a dynamically resized radial keyboard with randomized rotation to enhance security against inference attacks, while analyzing usability tradeoffs and future improvements.

Contribution

Introduces a novel radial keyboard design with dynamic resizing and random rotation for secure VR text entry, addressing vulnerabilities in existing methods.

Findings

Significantly improves resistance to keystroke prediction attacks

Increases entry time and subjective workload compared to standard QWERTY

Shows potential for performance gains with practice

Abstract

As virtual reality (VR) becomes more widely adopted, secure and efficient text entry is an increasingly critical need. In this paper, we identify a vulnerability in a state-of-the-art secure VR text entry method and introduce a novel virtual radial keyboard designed to achieve a balance between security with usability. Keys are arranged alphabetically in a circular layout, with each key selected by controller rotation and dynamically expanding to facilitate precise selection. A randomized rotation mechanism shifts the keyboard after each keystroke, preserving relative key positions while disrupting absolute spatial mappings to protect against inference attacks. We conducted a within-subject study (N=30) comparing our method with the prior secure technique and a standard QWERTY keyboard. Results showed that the radial keyboard significantly improves resistance to keystroke prediction attacks while incurring a tradeoff in entry speed and subjective workload due to the unfamiliar non-QWERTY layout. However, both quantitative trends and qualitative feedback indicate strong potential for performance improvements with practice. We also discuss design implications, possible interface refinements, and directions for future work, including layout variations and visual enhancements.