Title: Secure Verifiable Delegated Computation in the Cloud: A Case Study of Private Set Intersection

Speaker: Dr. Dong Changyu, School of Computing Science, Newcastle University, UK

Time: 9:00am-10:00am, May 29, 2016

Venue: Room 202, Office Building, Software Campus

Host: Prof. Xu Qiuliang

ABSTRACT:  Cloud computing has become increasingly popular. A report by IDG reveals that in 2015, 72% of organisations have at least one application in the cloud or a portion of their computing infrastructure in the cloud, up 15% from 2012. By providing shared processing resources on demand, cloud computing offers several key benefits to businesses. However cloud computing is by its very nature a service offered by an external party. Since the cloud provider is another organisation other than the user, their interests may point in different directions. It is difficult for the user to fully trust the cloud. The lack of trust in the cloud means that the effectiveness and efficiency of traditional security protection mechanisms need to be reconsidered, and new mechanisms are needed to compensate the missing trust.

Ideally in an environment like the cloud, we would like secure verifiable delegated computation. This entails a few things: the data can be securely stored on the untrusted cloud, the computation is carried out by the untrusted cloud who should not learn anything from it, and the user can verify the result is correct and the correct input are used. However, in general this is not possible without fully homomorphic encryption which is far from practical at the moment. In this talk, I will describe an efficient protocol that enable secure verifiable delegated computation of a specific data processing task, namely computing the intersection of two private sets. I will start from a protocol that provides only confidentiality and then extend to the case where integrity verification is included. The protocol does not require FHE and thus is more practical.

BIOGRAPHY: Changyu Dong is a senior lecturer at Newcastle University, UK. He obtained his PhD from the Department of Computing at Imperial College London in 2009. His research is in cyber security, specifically in applied cryptography. Since 2006, He has published 30 research papers in major journals and international conferences, including the most prestigious venues in security such as ACM CCS, ESORICS and Journal of Computer Security. He has served on and chaired program committees for many conferences and workshops, and is a regular invited reviewer for top international journals including Journal of Computer Security, IEEE Transactions on Dependable and Secure Computing and IEEE Transactions on Information Forensics and Security. Since 2011, he started his research on efficient secure computation. This research direction has led to some breakthroughs in secure computing for Private Set Intersection and Private Information Retrieval protocols, which he applied in domains such as data mining. 

Homepage：http://homepages.cs.ncl.ac.uk/changyu.dong/