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

2026-01-09

arXiv.org

AI Summary

This work proposes a novel virtual radial keyboard to address the vulnerability of text entry in virtual reality to inference attacks. The design employs a circular letter layout, where users select keys by rotating a controller, complemented by dynamic key expansion to enhance input accuracy. To thwart keystroke prediction attacks, a non-intrusive random rotation mechanism is introduced after each keystroke, disrupting absolute spatial mappings while preserving relative key positions. User studies demonstrate that this approach significantly improves security. Although the non-QWERTY layout initially reduces typing speed and increases subjective workload, the results indicate substantial potential for performance improvement with practice, thereby achieving a new balance between security and usability.

Technology Category

• Humans and AI: Game Design — Virtual Humans, NPCs and Autonomous Characters
• Computer Vision: Adversarial Attacks & Robustness
• Natural Language Processing: Safety and Robustness

Application Category

• Security and Privacy: Large-scale security measurements
• User Modeling, Personalization and Recommendation: Attacks and countermeasures in recommendation systems
• Responsible Web: Data and user privacy-enhancing technologies for the Web

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.

Problem

• secure text entry
• virtual reality
• keystroke inference attack
• usability
• VR security

Innovation

• virtual radial keyboard
• dynamic key resizing
• non-intrusive randomization
• keystroke inference attack
• VR text entry