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.

翻译：随着虚拟现实（VR）技术的日益普及，安全高效的文本输入需求变得愈发关键。本文识别了一种先进的安全VR文本输入方法中存在的安全漏洞，并提出一种新颖的虚拟径向键盘设计，旨在实现安全性与可用性之间的平衡。该键盘采用字母顺序排列的环形布局，用户通过控制器旋转进行按键选择，且按键会动态扩展以辅助精确选取。随机化旋转机制在每次击键后对键盘进行整体偏移，在保持按键相对位置不变的同时破坏绝对空间映射关系，从而有效防御推断攻击。我们开展了一项被试内实验（N=30），将本方法与先前的安全技术及标准QWERTY键盘进行对比。结果表明：径向键盘在显著提升抗击键预测攻击能力的同时，由于非QWERTY布局的陌生性，在输入速度与主观工作负荷方面存在性能权衡。然而，定量趋势与定性反馈均表明，通过练习该方法具有显著提升操作性能的潜力。本文进一步探讨了设计启示、可能的界面优化方案以及未来研究方向，包括布局变体设计与视觉增强策略。