數位微流體生物晶片因為低消耗、便利攜帶性和高效率的關係，在現今的健康照護產業中扮演著重要角色。根據最新的市場調查報告，生物晶片的市值成長率是往年的兩倍以上。然而隨著市值的巨大成長，利用侵權行為來獲取不法所得也成了一大威脅。為了防止侵權行為，傳統方法上是利用密鑰來授權。然而，數位微流體生物晶片上並沒有複雜的記憶體和邏輯閘來儲存密鑰，因此設計防護方法變得更加困難。在這篇論文中，我們提出了第一個利用最新物理不可克隆函數(PUF)來授權數位微流體生物晶片的防護方法。我們提出的物理不可克隆函數(PUF)利用了數位微流體生物晶片上固有的變異來生產密鑰，因此不需要使用記憶體。最後，我們分析了提出的方法的安全性，實驗也顯示出此方法的可行性。

Digital microfluidic biochips (DMFBs) play an important role in the healthcare industry due to its advantages such as low-cost, portability, and efficiency. According to the recent market report, the growth of biochips market is twice than before. However, as the
enormous business opportunities grow, piracy attacks, which are exploited by unscrupulous people to gain illegal profits, become a severe threat to DMFBs. To prevent piracy attacks, the conventional approach uses secret keys to perform authentication. Nevertheless,
DMFBs only consist of electrodes to control the operations of droplets, and there are no memories and logic gates integrated on it to store secret keys. This makes designing secure defenses of DMFBs against piracy attacks more dicult. Thus, in this thesis, we propose the first authentication method for piracy prevention of DMFBs based on a novel Physical Unclonable Function (PUF). The proposed PUF utilizes the inherent variation of electrodes on DMFBs to generate secret keys, so it does not require memory. Experimental
results demonstrate the feasibility of our proposed PUF. Finally, we analyze the security of the proposed method against piracy attacks.

Acknowledgement i
Abstract ii
1 Introduction 1
1.1 Digital Microfluidic Biochip . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Motivations for attacking DMFBs . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Security Vulnerabilities of DMFBs . . . . . . . . . . . . . . . . . . . . . . 2
1.4 Digital Right Management . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.5 Physical Unclonable Function . . . . . . . . . . . . . . . . . . . . . . . . 4
1.6 Contribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Background 6
2.1 Digital Microfluidic Biochip (DMFB) . . . . . . . . . . . . . . . . . . . . 6
2.1.1 Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.2 Design Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Piracy Attacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.2.1 Piracys impact . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.3 Physical Unclonable Function (PUF) . . . . . . . . . . . . . . . . . . . . . 12
iii
2.3.1 PUF classification . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3 DRM model for DMFBs 15
3.1 Design Flow of DMFBs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.2 Principle of the DRM Process . . . . . . . . . . . . . . . . . . . . . . . . 17
3.3 Lock/Unlock DMFBs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.3.1 Lock method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.3.2 Unlock method . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4 Developed PUFs for DMFBs 23
4.1 Route PUF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.2 Split PUF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
4.3 Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5 The Security Analysis 30
5.1 Brute force . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.2 Simulating PUF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
5.3 Reverse engineering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
5.4 Counterfeiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
6 Conclusion 32
References 33

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