We propose Breath to Pair (B2P), a protocol for pairing and shared-key generation for wearable devices that leverages the wearer's respiration activity to ensure that the devices are part of the same body-area network. We assume that the devices exploit different types of sensors to extract and process the respiration signal. We illustrate B2P for the case of two devices that use respiratory inductance plethysmography (RIP) and accelerometer sensors, respectively. Allowing for different types of sensors in pairing allows us to include wearable devices that use a variety of different sensors. In practice, this form of sensor variety creates a number of challenges that limit the ability of the shared-key establishment algorithm to generate matching keys. The two main obstacles are the lack of synchronization across the devices and the need for correct noise-induced mismatches between the generated key bit-strings. B2P addresses the synchronization challenge by utilizing Change Point Detection (CPD) to detect abrupt changes in the respiration signal and consider their occurrences as synchronizing points. Any potential mismatches are handled by optimal quantization and encoding of the respiration signal in order to maximize the error correction rate and minimize the message overheads. Extensive evaluation on a dataset collected from 30 volunteers demonstrates that our protocol can generate a secure 256-bit key every 2.85 seconds (around one breathing cycle). Particular attention is given to secure B2P against device impersonation attacks.

中文翻译：

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呼吸配对 (B2P)：基于呼吸的可穿戴设备配对协议

我们提出了 Breath to Pair (B2P)，这是一种用于可穿戴设备的配对和共享密钥生成的协议，它利用佩戴者的呼吸活动来确保设备是同一身体区域网络的一部分。我们假设设备利用不同类型的传感器来提取和处理呼吸信号。我们分别针对使用呼吸电感体积描记 (RIP) 和加速度计传感器的两个设备来说明 B2P。允许配对不同类型的传感器使我们能够包括使用各种不同传感器的可穿戴设备。在实践中，这种传感器种类的形式带来了许多挑战，限制了共享密钥建立算法生成匹配密钥的能力。两个主要障碍是设备之间缺乏同步，以及需要在生成的密钥位串之间纠正噪声引起的不匹配。B2P 通过利用变化点检测 (CPD) 来检测呼吸信号中的突然变化并将它们的出现视为同步点来解决同步挑战。任何潜在的不匹配都通过呼吸信号的最佳量化和编码来处理，以最大化纠错率并最小化消息开销。对从 30 名志愿者收集的数据集进行的广泛评估表明，我们的协议可以每 2.85 秒（大约一个呼吸周期）生成一个安全的 256 位密钥。特别注意保护 B2P 免受设备模拟攻击。