About Me

I am a visiting post-doctoral research fellow in the School of Computing Science at Simon Fraser University working with Prof. Jian PEI.

I obtained my Ph.D. degree from the Computer Science Department at Hong Kong Baptist University, advised by Prof. Jianliang XU. I am a member of the Database Group and the Blockchain & FinTech Lab. Prior to that, I obtained my Bachelor degree from the School of Electronic Information and Communications, Huazhong University of Science and Technology.

Research Interests

I am interested in Databases, Blockchain, Cryptography, Information Security, and Privacy-Aware Computing. My current focuses include:

• Authenticated query processing for outsourcing cloud computing.
• Searchable blockchain with integrity assurance.
• Privacy preserving query processing and access control.

Publications [Google Scholar] [DBLP]

• C. Xu, C. Zhang, J. Xu, and J. Pei, “SlimChain: Scaling Blockchain Transactions through Off-Chain Storage and Parallel Processing,” Proceedings of the VLDB Endowment (PVLDB), vol. 14, no. 11, pp. 2314–2326, Jul. 2021, doi: 10.14778/3476249.3476283. Full Paper. [eprint] [tech. report] [slides] [poster] [video] [code]
• Z. Peng, C. Xu, H. Wang, J. Huang, J. Xu, and X. Chu, “P²B-Trace: Privacy-Preserving Blockchain-based Contact Tracing to Combat Pandemics,” in Proceedings of the 2021 ACM SIGMOD International Conference on Management of Data (SIGMOD ’21), Xi'an, Shaanxi, China, 2021, pp. 2389–2393, doi: 10.1145/3448016.3459237. Short Paper. [pdf] [eprint] [video]
• C. Zhang, C. Xu, H. Wang, J. Xu, and B. Choi, “Authenticated Keyword Search in Scalable Hybrid-Storage Blockchains,” in Proceedings of the 37th IEEE International Conference on Data Engineering (ICDE ’21), Chania, Crete, Greece, 2021, pp. 996–1007, doi: 10.1109/ICDE51399.2021.00091. Full Paper. [pdf] [eprint] [slides]
• K. Li, Y. Tang, J. Chen, Z. Yuan, C. Xu, and J. Xu, “Cost-Effective Data Feeds to Blockchains via Workload-Adaptive Data Replication,” in Proceedings of the 21st International Middleware Conference (Middleware ’20), Delft, Netherlands, 2020, pp. 371–385, doi: 10.1145/3423211.3425696. Full Paper. [pdf]
• H. Wang, C. Xu, C. Zhang, and J. Xu, “vChain: A Blockchain System Ensuring Query Integrity,” in Proceedings of the 2020 ACM SIGMOD International Conference on Management of Data (SIGMOD ’20), Portland, OR, USA, 2020, pp. 2693–2696, doi: 10.1145/3318464.3384682. Demo Paper. [pdf] [eprint] [video] [code]
• S. Guo, Y. Ji, C. Zhang, C. Xu, and J. Xu, “vCBIR: A Verifiable Search Engine for Content-Based Image Retrieval,” in Proceedings of the 36th IEEE International Conference on Data Engineering (ICDE ’20), Dallas, TX, USA, 2020, pp. 1730–1733, doi: 10.1109/ICDE48307.2020.00156. Demo Paper. [pdf]
• C. Xu, C. Zhang, and J. Xu, “vChain: Enabling Verifiable Boolean Range Queries over Blockchain Databases,” in Proceedings of the 2019 ACM SIGMOD International Conference on Management of Data (SIGMOD ’19), Amsterdam, Netherlands, 2019, pp. 141–158, doi: 10.1145/3299869.3300083. Full Paper. [pdf] [eprint] [slides] [poster] [code]
• Y. Ji, C. Xu, J. Xu, and H. Hu, “vABS: Towards Verifiable Attribute-Based Search over Shared Cloud Data,” in Proceedings of the 35th IEEE International Conference on Data Engineering (ICDE ’19), Macau SAR, China, 2019, pp. 2028–2031, doi: 10.1109/ICDE.2019.00231. Demo Paper. [pdf] [eprint] [poster]
• S. Guo, J. Xu, C. Zhang, C. Xu, and T. Xiang, “ImageProof: Enabling Authentication for Large-Scale Image Retrieval,” in Proceedings of the 35th IEEE International Conference on Data Engineering (ICDE ’19), Macau SAR, China, 2019, pp. 1070–1081, doi: 10.1109/ICDE.2019.00099. Full Paper. [pdf] [eprint] [slides] [poster]
• C. Zhang, C. Xu, J. Xu, Y. Tang, and B. Choi, “GEM²-Tree: A Gas-Efficient Structure for Authenticated Range Queries in Blockchain,” in Proceedings of the 35th IEEE International Conference on Data Engineering (ICDE ’19), Macau SAR, China, 2019, pp. 842–853, doi: 10.1109/ICDE.2019.00080. Full Paper. [pdf] [eprint] [slides] [poster]
• C. Xu, J. Xu, H. Hu, and M. H. Au, “When Query Authentication Meets Fine-Grained Access Control: A Zero-Knowledge Approach,” in Proceedings of the 2018 ACM SIGMOD International Conference on Management of Data (SIGMOD ’18), Houston, TX, USA, 2018, pp. 147–162, doi: 10.1145/3183713.3183741. Full Paper. [pdf] [eprint] [slides] [poster]
• C. Zhang, C. Xu, J. Xu, and B. Choi, “Distributed kNN Query Authentication,” in Proceedings of the 19th IEEE International Conference on Mobile Data Management (MDM ’18), Aalborg, Denmark, 2018, pp. 167–176, doi: 10.1109/mdm.2018.00034. Full Paper. [pdf] [eprint]
• C. Xu, Q. Chen, H. Hu, J. Xu, and X. Hei, “Authenticating Aggregate Queries over Set-Valued Data with Confidentiality,” IEEE Transactions on Knowledge and Data Engineering (TKDE), vol. 30, no. 4, pp. 630–644, Apr. 2018, doi: 10.1109/TKDE.2017.2773541. Full Paper. [pdf] [eprint] [poster]
• C. Xu, Q. Chen, H. Hu, J. Xu, and X. Hei, “Authenticating Aggregate Queries over Set-Valued Data with Confidentiality (Extended Abstract),” in Proceedings of the 34th IEEE International Conference on Data Engineering (ICDE ’18), Paris, France, 2018, pp. 1797–1798, doi: 10.1109/ICDE.2018.00256. Poster Paper. [pdf] [eprint] [poster]
• Y. Tang, Z. Xing, C. Xu, J. Chen, and J. Xu, “Lightweight Logging over the Blockchain for Data-Intensive Applications,” in 2nd Workshop on Trusted Smart Contracts at International Conference on Financial Cryptography and Data Security, Santa Barbara Beach Resort, Curaçao, 2018, pp. 308–324, doi: 10.1007/978-3-662-58820-8_21. Workshop Paper. [pdf]
• Q. Zhu, H. Hu, C. Xu, J. Xu, and W.-C. Lee, “Geo-social group queries with minimum acquaintance constraints,” The VLDB Journal (VLDBJ), vol. 26, no. 5, pp. 709–727, Jul. 2017, doi: 10.1007/s00778-017-0473-6. Full Paper. [pdf] [eprint] [poster]

Talks

• Blockchain Privacy Preserving Techniques, The 36th CCF National Database Conference, Jinan, China, Oct. 12, 2019. [link] [slides]
• Towards Searchable and Verifiable Blockchain, 1st Workshop on Blockchain and Data Management at 35th IEEE International Conference on Data Engineering, Macau, Apr. 8, 2019. [link] [slides]
• When Query Authentication Meets Fine-Grained Access Control: A Zero-Knowledge Approach, 2018 ACM SIGMOD International Conference on Management of Data, Houston, TX, USA, Jun. 12, 2018. [link] [slides]