主動式遠端免鑰匙遙控器(RemoteKeyless Entry ; RKE)常用於汽車及家用車庫門 鎖，用來悶、關鎖。此一兔鑰匙RKE系統簡單，但需使用者手按遙控器上的按鈕來操作。結合無線射頻辨識�統(RadioFrequency Identification; RFID)的被動式風應運作原 理，可以讓RKE系統變成無需手動按鈕的被動式免鑰匙進入系統(PassiveKeyless Entry; PKE)。此一新的系統，應用於家用門鎖的問鎖。使用者身上的應答� (Transponder) 如同遙控器，平時進入睡眠省電模式，但經由門鎖設備以125kHz低頻無線電信號來喚醒，以進行後續UHF超高頻無線電方式的自動認證。此一動作，被設計在使用者閉門的同時，門鎖設備自動發出低頻喚醒信號，屆主動應答器自動進行認證動作。因此，應答器可以達到省電目標，使用UHF工作頻率亦可增加無線電通信距離。本論文考慮應用於家用門鎖的兔鑰匙開鎖系統，並就應用時的某些可能問題進行探討。率統分為兩部分，分別為門鎖設備之讀取器(Reader)與使用者身上之應答器。為提高安全性，兩者使用128位元之相同密鑰來進行盤查/回應(Challenge/response)認證，且設計以流水號(Sequence numbel切口密來取代複雜的亂數產生器。加解密方法使用可簡單軟體實現之 AES-128演算法，進行高安全認證機制，以阻止各種可能的安全攻擊。通信碰撞(Collision) 問題，採用不同的防碰撞機制，以減少訊息傳輸碰撞機率，增加�統使用效率。

Remote Keyless Entry (RKE) 1S often used in the vehicles and garage to lock or unlock the door. The RKE can easily be used， users canγa fob and press the lock or unlock buttons. By combining the passive induction coupling of Radio Frequency Identification (RFID)， RKE may lead in another system， a Passive Keyless Entry (PKE) system， which can be applied in hands-free home door unlock system. Likesa remote controller， the user's transponder normally states in sleep mode， and is triggered by a low radio frequency (LF) signal， and subsequently uses an Ultra-high radio frequency (UHF) signal to take authentication with door's device. This step is initiated when user attempts to unlock door， the door device automatically sends a LF wakeup signal to trigger the user's transponder to take the authentication process. Therefore， the transponder can reduce the power consumption， and the use of UHF can increase the distance of radio frequency. 1n the article， we discuss the appliances of the home door unlock system and propose solutions to the possible problems. The system consists of two units， the reader at the lock device and the transponder at the user. In order to provide a higher lever of security， these two units share the same 128-bits secret-key and perform the challenge-response mechanism to authenticate each other. In order to simple the design， the encrypted sequence number is used to substitute the complex random generator， and the AES-128 algorithm is easily implemented by software. This security authentication can prevent from possible attacks. Col1ision problems are also solved by using different anti-collision mechanism to decrease signal collision and to increase system useful.