# Cryptography and Information Security Seminar (CIS)

 Ling Ren: Proof of Space from Stacked ExpandersFriday, October 21, 2016 - 10:30am to 12:00pmAbstract:  Recently, proof of space (PoS) has been suggested as a more egalitarian alternative to the traditional hash-based proof of work. Omer Paneth: On Obfuscation with Random OraclesFriday, April 10, 2015 - 10:30am to 12:00pmAbstract: Sergey Gorbunov: Graph-Induced Multilinear Maps from LatticesFriday, April 24, 2015 - 10:30am to 12:00pmGraded multilinear encodings have found extensive applications in cryptography ranging from non-interactive key ex On Virtual Grey Box Obfuscation for General CircuitsFriday, October 17, 2014 - 10:30am to 12:00pmAbstract: An obfuscator $\O$ is Virtual Grey Box (VGB) for a class $\C$ of circuits if, for any $C \in \C$ and any predicate $\pi$, deducing $\pi(C)$ given $\O(C)$ is tantamount to deducing $\pi(C)$ given unbounded computational resources and polynomially many oracle queries to \$ Sum of Squares Proofs and the Quest towards Optimal AlgorithmsWednesday, September 3, 2014 - 10:00am Elette Boyle: Large-Scale Secure ComputationFriday, July 25, 2014 - 10:30am to 12:00pm Manoj M. Prabhakaran "The Communication Complexity of Secure Computation"Thursday, July 10, 2014 - 11:00am to 12:00pmInformation theoretically secure multi-party computation(MPC) is a central primitive of modern cryptography. However, relatively little is known about the communication complexity of this primitive. In this Brent Waters: Witness Encryption and Indistinguishability Obfuscation from the Multilinear Subgroup Elimination Assumption Friday, July 11, 2014 - 10:30am to 12:00pmIn this talk I will present new techniques for proving the security ofwitness encryption and indistinguishability obfuscation cryptosystems.Witness encryption and indistinguishability obfuscation are powerful