Adaptive Extractors and their Application to Leakage Resilient Secret Sharing

A Leakage Resilient Secret Sharing (LRSS) is a secure secret sharing scheme, even when the adversary obtains some (bounded) leakage on honest shares. Ideally, such schemes must be secure against adaptive and joint leakage queries – i.e., the adversary can make a sequence of adaptive leakage queries where each query can be a joint function of many of the shares. In this work, we provide the first constant rate LRSS (for the general access structure) and non-malleable LRSS (for the threshold access structure) schemes that tolerate such joint and adaptive leakage in the information-theoretic setting. We show how to make use of our constructions to also provide constant rate constructions of leakage-resilient (and non-malleable) secure message transmission.

This is joint work with Nishanth Chandran and Sai Lakshmi Bhavana Obbattu from Microsoft Research India and Sruthi Sekar from IISc.



Nishanth Chandran, Bhavana Kanukurthi, Sai Lakshmi Bhavana Obbattu, Sruthi Sekar. Adaptive Extractors and their Application to Leakage Resilience Secret Sharing, CRYPTO 2021 [41st  IACR International Conference on Cryptology]
Faculty: Bhavana Kanukurthi, CSA
Click image to view enlarged version

Scroll Up