Speaker: Hongsheng Zhou University of Maryland
Time: 2011-06-08 10:30-2011-06-08 11:30
Venue: FIT 1-222
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Abstract:

In contemporary network settings such as the Internet, a protocol will be concurrently executed with other protocols; it is well-known in such settings that traditional stand-alone security analysis is insufficient. The notion of Universal Composability (UC) by Canetti addresses this issue, and protocols satisfying UC security are guaranteed to remain secure in any protocol environment.

In this talk we will overview our results in the area and go in more depth in designing efficient secure protocols against adaptive adversaries. We present a new approach to achieve adaptive security in the UC framework. More specifically, we first introduce a new notion called "semi-adaptive security" which is slightly stronger than static security but significantly weaker than fully adaptive security. Then we give a simple, generic protocol compiler to transform any semi-adaptively secure protocol into a fully adaptively secure one. We demonstrate the power of this new approach by transforming the recent efficient -- but statically secure -- Oblivious Transfer (OT) protocol by Peikert et al. [Crypto '08] into the first efficient adaptively secure one.

Short Bio:

Hong-Sheng Zhou is a postdoctoral researcher at University of Maryland under the direction of Professor Jonathan Katz. Hong-Sheng completed his Ph.D. at the University of Connecticut in 2010 under the supervision of Professor Aggelos Kiayias. His research interests are in the field of Cryptography.