Three papers by academics from the Cryptography Group at Bristol University’s Department of Computer Science will be presented at the ASIACRYPT conference in Tokyo this week, 6th to 10th December 2009.
"Security Notions and Generic Constructions for Client Puzzles" will discuss the defence for websites against attackers who launch denial-of-service attacks. Such attacks are becoming more common on the internet, with high-profile attacks taking place against many leading websites. The paper, from research by Bristol University academics, Paul Morrissey, Nigel Smart, Bogdan Warinschi and Liqun Chen from Hewlett-Packard Laboratories in Bristol, investigates a specific defence technique that aims to make performing such attacks computationally infeasible, while not overburdening the innocent user.
In joint research between Nigel Smart and Steve Williams at Bristol University; Benny Pinkas, University of Haifa, Israel and Thomas Schneider, Ruhr-University at Bochum, Germany, the team show that a procedure thought to be only theoretical can actually be implemented in practice. One goal of this collaboration, entitled "Secure Two-Party Computation is Practical", is to ultimately allow for databases to compute on encrypted data. Future applications of this research could allow doctors to access centralised healthcare databases in a way that protects patient confidentiality.
In the final paper, "Foundations of Non-Malleable Hash and One-Way Functions", by Bogdan Warinschi from Bristol University; Alexandra Boldyreva and David Cash, Georgia Institute of Technology, USA and Marc Fischlin, Technical University in Darmstadt, Germany, the researchers consider foundational issues related to basic constructions in cryptography. This research is an important step in understanding the properties of a cryptographic object called a "random oracle". Such objects are a popular solution in constructing efficient cryptographic schemes, such as those used in a web browser.
ASIACRYPT is held annually in a different city in the Asia-Pacific region and is one of the three flagship conferences of the International Association for Cryptologic Research. The other two conferences are: CRYPTO, held annually in Santa Barbara California, and EUROCRYPT held annually in a different European city.
Nigel Smart, Professor of Cryptology in the Department of Computer Science at the University of Bristol and co-author on two of the papers, said: "We are delighted to have such a strong presence at this year’s ASIACRYPT conference, especially as it was particularly hard to have papers accepted. Of 300 submissions, just over 40 were selected for presentation at the conference."
The Bristol component of the work in the three papers is partly funded by two grants from the European Union (eCrypt-2 and CACE), the EPSRC (via a doctoral training grant) and the Royal Society.