We consider a wireless communication system with a passive eavesdropper, in which a transmitter and legitimate receiver generate and use key bits to secure the transmission of their data. These bits are added to and used from a pool of available key bits. In this work, we analyze the reliability in terms of the probability that the budget of available key bits will be exhausted. In addition, we investigate the latency before a transmission can take place. Since security, reliability, and latency are three important metrics for modern communication systems, it is of great interest to jointly analyze them in relation to the system parameters. Interestingly, we show under what conditions the system may remain in an active state indefinitely, i.e., never run out of available secret-key bits. The results presented in this work can be used by system designers to adjust the system parameters in such a way that the requirements of the application in terms of both reliability and latency are met.

翻译：本文考虑存在被动窃听者的无线通信系统，其中发射机和合法接收机生成并使用密钥比特来保护数据传输的安全性。这些比特被添加至可用密钥比特池中并从中消耗。本研究从可用密钥比特预算耗尽概率的角度分析了系统的可靠性，同时探讨了传输前可能出现的延迟。由于安全性、可靠性与延迟是现代通信系统的三大重要指标，联合分析它们与系统参数的关系具有重要意义。有趣的是，我们揭示了系统在何种条件下能够无限期保持活跃状态，即永远不会耗尽可用密钥比特。本文所得结果可供系统设计人员用于调整系统参数，从而满足应用对可靠性与延迟的双重要求。