配備喚醒無線電的物聯網設備可以使用超低功耗的喚醒接收器來監控頻道，而主要無線電收發器可以保持省電的睡眠模式，直到喚醒接收器收到其他物聯網設備的喚醒令牌（WuT）。但是裝備喚醒無線電的設備容易受到拒絕睡眠攻擊，攻擊者可以通過監聽頻道輕鬆獲取舊的喚醒令牌，並多次重播舊的喚醒令牌喚醒目標設備，這將快速耗盡設備的電池並縮短設備壽命。另外，物聯網設備的體積小，方便佈署物聯網設備在戶外的環境中收集感測數據。然而，攻擊者可以透過捕獲物聯網設備，更進一步訪問設備的非防篡改記憶體來獲取秘密訊息並將秘密資訊複製到其他設備，偽裝成真正的物聯網設備來進行其他攻擊。
為了解決上述問題，我們對於想加入物聯網的設備設計身份認證和喚醒令牌的建立機制，使設備和閘道可以互相驗證對方身份並建立一次性喚醒令牌，並且設計喚醒令牌的更新和重新同步閘道和設備之間的非同步喚醒令牌，確保設備不會因為非同步的喚醒令牌而無法被喚醒。另外，為了提高通信效率並節省能源，設計了組喚醒令牌的建立機制。本研究提出的機制使用了物理不可仿製功能(Physical Unclonable Function)來生成金鑰並保護存儲在記憶體中的秘密訊息免於物理和克隆攻擊。最後，通過邏輯分析和實作證明本機制的正確性和可行性。

Wake-up radio (WuR) is an ultra-low-power hardware component to monitor the channel all the time. An IoT device equipped with a wake-up radio usually puts its main radio in a power-saving sleep mode while not conducting any communication to conserve energy. Upon receiving a pre-defined pattern called Wake-up Token (WuT) on the WuR, the IoT device turns on its main transceiver to conduct communication. However, WuR-based devices are susceptible to the Denial-of-Sleep attack as an attacker can quickly drain all their energy and put them out of service by eavesdropping and replay the WuT. On the other hand, an adversary can also conduct cloning attacks on a legitimate IoT device and then launches impersonation attacks.
To resolve the aforementioned problems, we design an identity authentication and wake-up token establishment scheme for IoT devices with the Physical Unclonable Function (PUF). The proposed scheme allows IoT devices to conduct mutual authentication and establish a one-time encryption key and a one-time WuT between them. Furthermore, a WuT update and resynchronization scheme is designed to make sure that the WuT between the communication parties is always synchronized. To defend the cloning attacks, a strong PUF is used in the proposed scheme to generate secret keys and subsequently derive the WuTs. Hence, the proposed scheme is further extended to support group communication while enhancing communication efficiency and conserve energy. Finally, the correctness and feasibility of the proposed schemes are proved through logic analysis and implementation.

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