Mon, 03 Jun 2024 13:00 Lattice-Based Functional Commitments: Constructions and Cryptanalysis by David Wu (UT Austin)

A functional commitment allows a user to commit to an input x and later open up the commitment to a value f(x) for an arbitrary function f. We require that the size of the commitment and the size of the opening be sublinear in the length of the input x. In this talk, I first describe how to construct functional commitments from the recently-introduced \ell-succint SIS assumption (this is a falsifiable q-type generalization of the classic SIS assumption). Then, I will highlight some challenges in constructing lattice-based extractable functional commitments (which are equivalent to succinct non-interactive arguments of knowledge) and describe a (heuristic) attack on recently-proposed lattice-based knowledge assumptions underlying extractable functional commitments and SNARKs.

Based on joint work with Hoeteck Wee

Speaker Bio:

David Wu is an assistant professor in the Department of Computer Science at the University of Texas at Austin. He is broadly interested in applied and theoretical cryptography as well as computer security. Previously, David received a PhD in computer science from Stanford University in 2018 and was an assistant professor at the University of Virginia from 2019 to 2021. He has received the NSF CAREER Award, the Microsoft Research Faculty Fellowship, and a Google Research Scholar Award. His work has been recognized with a Best Paper Award at CRYPTO (2022), two Best Young-Researcher Paper Awards at CRYPTO (2017, 2018) and an Outstanding Paper Award at ESORICS (2016).

Venue: Online and at KCL