We conducted an online study with $n = 235$ Signal users on their understanding and usage of PINs in Signal. In our study, we observe a split in PIN management and composition strategies between users who can explain the purpose of the Signal PINs (56%; enthusiasts) and users who cannot (44%; casual users). Encouraging adoption of PINs by Signal appears quite successful: only 14% opted-out of setting a PIN entirely. Among those who did set a PIN, most enthusiasts had long, complex alphanumeric PINs generated by and saved in a password manager. Meanwhile more casual Signal users mostly relied on short numeric-only PINs. Our results suggest that better communication about the purpose of the Signal PIN could help more casual users understand the features PINs enable (such as that it is not simply a personal identification number). This communication could encourage a stronger security posture.

中文翻译：

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“我不知道他们想要完成什么：” 热情而随意的信号用户对信号 PIN 的理解

我们对 $n = 235$ Signal 用户进行了一项在线研究，了解他们对 Signal 中 PIN 的理解和使用。在我们的研究中，我们观察到可以解释信号 PIN 目的的用户（56%；爱好者）和不能解释信号 PIN 的用户（44%；临时用户）在 PIN 管理和组合策略方面存在分歧。Signal 鼓励采用 PIN 似乎非常成功：只有 14% 的人选择不完全设置 PIN。在那些确实设置了 PIN 的人中，大多数爱好者都拥有由密码管理器生成并保存在其中的长而复杂的字母数字 PIN。与此同时，更随意的 Signal 用户大多依赖于仅包含数字的短 PIN。我们的结果表明，就信号 PIN 的用途进行更好的沟通可以帮助更多的临时用户了解 PIN 启用的功能（例如，它不仅仅是个人识别码）。