Colloquium Speaker Prof. Dan Boneh, Stanford University Wednesday, October 19, 4:30pm Computer Science 105 Hiding the metadata in chat systems The talk will survey a number of open problems in computer security, and discuss recent progress on communication systems that hide the metadata. We will present a recent system, called Riposte, that uses cryptographic techniques to provide anonymous Tweets for very large anonymity sets. This is joint work with Henry Corrigan-Gibbs and David Mazieres. Dr. Boneh is a Professor of Computer Science at Stanford University where he heads the applied cryptography group and co-directs the computer security lab. Dr. Boneh's research focuses on applications of cryptography to computer security. His work includes cryptosystems with novel properties, security for mobile devices, web security, and cryptanalysis. He is the author of over a 150 publications in the field and is a recipient of the 2014 ACM Infosys award, the 2013 Godel prize, and the Ishii award for education.