Academic reports of Network Security

Type of Event: Academic reports of Network Security

Time: 08:30-11:30

Date: 2017-4-21

Venue: 622 meeting room of School of Computer Science, Wenjin Building

Hosted by: School of Computer Science

Schedule of Event:

Title of Lecture 1：A secure and obfuscated re-encryption machanism

Time:  8:30-9:30

Lecturer：Prof. Zhang Mingwu

Profile of the Lecture：

Re-encryption is a cryptographic primitive that converts a ciphertext of user A to another of user B. Traditionally, the re-encryption is proceeded by a proxy. However, as it needs a re-encryption key that might hide the sentitive information such as the sender an/or receiver secret key, then the proxy must be fully trusted. If the re-encryption is executed by a untrusted/malicious cloud server, and the cloud server can trace into the program or monitor the executing, the malicious server can obtain the sensitive information during the execution. In this talk, we give a secure and obfuscated re-encryption machanism to run on any malicious server while the sensitive information is fully protected even the server having access to the re-encryption program in a white-box manner. The algorithm can be used in the securely encrypted email delivery systems. 

Profile of the Lecturer：

Dr. Mingwu Zhang is now a professor at the School of Computer Sciences in Hubei University of Technology. Prior to joining HBUT, supported by Japan Society of the Promption of Sciences (JSPS), he has been a JSPS postdoctoral fellow at Faculty of Mathematics in Kyushu University from August 2010 to March 2011. and Institute of Mathematics for Industry in Kyushu University in Japan from April 2011 to August 2012 respectively, and also a CSC scholar at School of Computing and Information Technology in University of Wollongong, Australia from June 2015 to June 2016. He was an awarded by talent plan of “Chuntian scholarship” in 2012.

Title of Lecture 2：Anonymous authentication protocols for multi-server architectures

Time:  9:30-10:30

Lecturer：vice Prof. He Debiao

Profile of the Lecture :

With the development of computer science and network technology, an increasing number of Internet services are provided for users. Since the computational resources, transmission and storage capabilities of a single server are very limited; the traditional single-server environment cannot satisfy the requirements for most applications. To improve the performance of systems, the multi-server environment has been widely concerned and applied in many areas. Anonymous authentication is used to verify the consistency between the real identity and the claimed identity of users, which is one of the important measures to maintain the system security and protect user privacy in the multi-server environment. Through the analysis of existing work, we concluded the security requirements of systems and divided the anonymity into three levels. Furthermore, we designed a series of anonymous authentication protocols for multi-server environment, which satisfy the different requirements of users in terms of performance and security.

Profile of the Lecturer：

 Debiao He received his Ph.D. degree in applied mathematics from School of Mathematics and Statistics, Wuhan University in 2009. He is currently a vice professor of Wuhan University. His main research interests include cryptography and information security, in particular, cryptographic protocols. He has published more than 50 papers in some famous journals, such as IEEE Transactions on Information Forensics and Security，IEEE Transactions on  Dependable and Secure Computing，IEEE Transactions on Consumer Electronics，IEEE Systems Journal，IEEE Internet of Things Journal，IEEE Communications Magazine and IET Information Security.

Title of Lecture 3：A secret sharing scheme based on hyperplane geometry

Time:  10:30-11:30

Lecturer：vice Prof. Xia Zhe

Profile of the Lecture：

Secret sharing allows the secret to be shared among a number of parties, so that a quorum of these parties can collaborate to recover the secret, but less than a quorum of parties cannot learn any information of the secret. The secret sharing based on hyperplane geometry was introduced by Blakley in 1979, but it has not attracted many interests in the literature. Many of its potentials are yet to be investigated. In this talk, we revisit the secret sharing based on hyperplane geometry, and introduce some of its new properties and applications. The main contents include: 1) we show that hyperplane geometry is a useful technique to justify the perfect property of secret sharing schemes. Based on our results, many existing multi-secret sharing schemes can be shown failing to achieve the perfect property; 2) when designing threshold RSA/Paillier encryption using hyperplane geometry, we can completely avoid the problem of computing inverse in the group whose order is unknown. Moreover, compared with similar schemes based on polynomial interpolation, our scheme enjoys better computational efficiency; 3) we show that secret sharing scheme based on hyperplane geometry can efficiently handle both (n, t) secret sharing and (n, n) secret sharing. Hence, it could be a very useful technique to design proactive secret sharing and compartment secret sharing. The benefit is that the target schemes can be analyzed easier in the UC model.

Profile of the Lecturer：

Zhe Xia is currently an Associate Professor in the School of Computer Science at Wuhan University of Surrey. He obtained his PhD degree from University of Surrey (UK) in 2009. After that, he has worked in University of Surrey as a Postdoc Research Fellow, involving in a project on theory and applications of verifiable voting systems. The research outcome, called the Prêt à Voter voting system, has been successfully used in the Victorian State of Australia in 2014. And this is the first time across the world that verifiable voting systems have been used in large scale. In recently years, Zhe Xia has published more than 30 academic papers in well known journals and conferences, including IEEE Trans. on Informaiton Forensics and Security, IET Information Security, USENIX Security Symposium (EVT workshop), ACISP, etc. He has been invited to write a chapter for the Computer and Information Security Handbook (2nd edition). Zhe Xia has served as PC member for many conferences and the Associate Editor for the Journal of Information Security and Application.