Searchable Encryption

1. Front Matter

   Pages i-xii

   PDF

2. Introduction

   • Kui Ren, Cong Wang

   Pages 1-15

3. Fundamental Cryptographic Algorithms and Technologies

   • Kui Ren, Cong Wang

   Pages 17-27

4. Searchable Encryption Semantics

   • Kui Ren, Cong Wang

   Pages 29-46

5. Recent Advancements on Functionality and Performance

   • Kui Ren, Cong Wang

   Pages 47-76

6. Security Impact of Leakage Profiles: Threats and Countermeasures

   • Kui Ren, Cong Wang

   Pages 77-105

7. Toward Fully Functional Encrypted Databases

   • Kui Ren, Cong Wang

   Pages 107-147

8. Conclusion

   • Kui Ren, Cong Wang

   Pages 149-152

9. Back Matter

   Pages 153-171

   PDF

This book comprehensively reviews searchable encryption, which represents a series of research developments that directly enable search functionality over encrypted data. The book majorly covers: 1) the design and implementation of encrypted search algorithms, data structures, and systems that facilitate various forms of search over always-encrypted databases; 2) different threat models, assumptions, and the related security guarantees, when using searchable encryption in the real-world settings; and 3) latest efforts in building full-fledged encrypted database systems that draw insights from searchable encryption constructions.


The book fits in the timely context, where the necessity of safeguarding important and sensitive data has been globally recognized. Traditional security measures, such as storing data behind network firewalls and layers of access control mechanisms to keep attackers out, are no longer sufficient to cope with the expandinglandscape of surging cyber threats. There is an urgent call to keep sensitive data always encrypted to protect the data at rest, in transit, and in use. Doing so guarantees data confidentiality for owners, even if the data is out of their hands, e.g., hosted at in-the-cloud databases. The daunting challenge is how to perform computation over encrypted data. As we unfold in this book, searchable encryption, as a specific line of research in this broadly defined area, has received tremendous advancements over the past decades.


This book is majorly oriented toward senior undergraduates, graduate students, and researchers, who want to work in the field and need extensive coverage of encrypted database research. It also targets security practitioners who want to make well-informed deployment choices of the latest advancements in searchable encryption for their targeted applications. Hopefully, this book will be beneficial in both regards.

• Searchable encryption
• encrypted database
• always-encrypted storage
• data confidentiality
• data encryption
• encrypted queries
• leakage profiles
• applied cryptography
• leakage-abuse attacks
• snapshot and persistent adversary
• hardware-assisted enclave
• trusted execution environment
• oblivious algorithms
• access pattern

• Zhejiang University, Hangzhou, China

  Kui Ren

• City University of Hong Kong, Kowloon Tong, Hong Kong

  Cong Wang

Kui Ren is a Professor and Associate Dean of College of Computer Science and Technology at Zhejiang University (ZJU), where he also directs the Institute of Cyber Science and Technology. Kui is a Fellow of ACM and IEEE. Before ZJU, he was SUNY Empire Innovation Professor at State University of New York at Buffalo. Kui’s current research interests include Data Security, IoT Security, AI Security, and Privacy. He received Guohua Distinguished Scholar Award of ZJU, IEEE CISTC Technical Recognition Award in 2017, SUNY Chancellor’s Research Excellence Award in 2017, Sigma Xi/IIT Research Excellence Award in 2012, and NSF CAREER Award in 2011. Kui has published more than 300 papers in peer-reviewed journals and conferences. He has received several Best Paper Awards and Test of Time Paper Award, including IEEE ICDCS’20, ACM MobiSys’20, IEEE INFOCOM’20, IEEE Globecom’19, ChinaCrypt’18, ACM ASIACCS’18, ICPADS’18, IEEE ICDCS’17, IWQoS’17, and ICNP’11. His H-index is 85, and his total citation has exceeded 40,000, according to Google Scholar (as of August 2022). He currently serves as an area/associate editor for ACM Trans. On Cyber Physical Systems, IEEE Trans. on Dependable and Secure Computing, IEEE Trans. on Service Computing, IEEE Trans. on Networking, IEEE Trans. on Mobile Computing, IEEE Wireless Communications, IEEE Internet of Things Journal, and Computer Networks. Among others, he currently serves as Chair of SIGSAC of ACM China Council, a member of ACM ASIACCS steering committee, and a member of S&T Committee of Ministry of Education of China.

Cong Wang is a Professor in the Department of Computer Science, City University of Hong Kong. His current research interests include data and network security, blockchain and decentralized applications, and privacy-enhancing technologies. He has been one of the Founding Members of the Young Academy of Sciences of Hong Kong since 2017, and has been conferred the RGC Research Fellow in 2021. He received the Outstanding Researcher Award (junior faculty) in 2019, the Outstanding Supervisor Award in 2017 and the President's Awards in 2019 and 2016, all from City University of Hong Kong. He is a co-recipient of the IEEE INFOCOM Test of Time Paper Award 2020, Best Paper Award of IEEE ICDCS 2020, Best Student Paper Award of IEEE ICDCS 2017, and Best Paper Award of IEEE ICPADS 2018 and MSN 2015. His research has been supported by multiple government research fund agencies, including National Natural Science Foundation of China, Hong Kong Research Grants Council, and Hong Kong Innovation and Technology Commission. He serves/has served as associate editor for IEEE Transactions on Dependable and Secure Computing, IEEE Internet of Things Journal and IEEE Networking Letters, and The Journal of Blockchain Research, and TPC co-chairs for a number of IEEE conferences and workshops. He is a fellow of the IEEE, and a member of the ACM.

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