SPEAKER: Joël Alwen TITLE: Trapdoors for Hard Lattices and New Cryptographic Constructions - Part II (IBE & LWE) AUTHORS: Craig gentry, Chris Peikert, Vino Vaikuntanathan (Proc. of STOC 2008) ABSTRACT: An important line of work presented in GPV08 concerns how to use the Learning With Errors (LWE) problem as an intermediate hardness assumption for lattice based cryptography. In particular a dual encryption scheme to that of Reg05 is given which has a very simple an elegant proof of CPA security reducing to the LWE problem. Next the dual cryptosystem is used as a building block to construct a lattice based IBE scheme in the RO model which enjoys both a clean proof of security as well as relative asymptotic efficiency (when compared with other existing IBE schemes). Finally the authors demonstrate new trapdoor methods for LWE via a public key encryption system secure under the LWE assumption. In this talk we will discuss these techniques, constructions and their proofs of security. ONLINE VERSION: http://people.csail.mit.edu/cpeikert/pubs/svpcrypto.pdf