George Lu - Succinctness and Adaptivity in Computational Secret Sharing скачать в хорошем качестве

George Lu - Succinctness and Adaptivity in Computational Secret Sharing

Abstract: Secret sharing (SS) is a foundational cryptographic primitive with diverse applications, including secure multiparty computation and conditional disclosure of secrets. While traditional schemes have primarily emphasized information-theoretic security, recent advancements have increasingly leveraged computational assumptions to achieve more efficient constructions and support broader access policies. In this talk, I will present two results: First, I will present a new construction of CSS for monotone circuits which is succinct, where the share size depends only on the number of parties and is independent of the circuit size. Our scheme is the first to achieve this level of succinctness and relies on indistinguishability obfuscation and one-way functions. Second, I will describe a general transformation that enhances any statically secure CSS scheme to adaptive security. This transformation uses only one-way functions and preserves the access policies of the original scheme, giving the first adaptively secure CSS schemes for several policy classes previously not known from the same assumptions as the corresponding static CSS schemes. Bio: George is a PhD student in cryptography at UT Austin advised by Brent Waters. He is broadly interested in theoretical crypto with a focus on advanced encryption and foundations.