LIPIcs - Leibniz International Proceedings in Informatics. 2nd Conference on Information-Theoretic Cryptography (ITC 2021)
Doi
Abstract
Correlated random variables are a key tool in cryptographic applications like secure multi-party computation. We investigate the power of a class of correlations that we term group correlations: A group correlation is a uniform distribution over pairs (x,y)∈G2 such that x+y∈S, where G is a (possibly non-abelian) group and S is a subset of G. We also introduce bi-affine correlations and show how they relate to group correlations. We present several structural results, new protocols, and applications of these correlations. The new applications include a completeness result for black-box group computation, perfectly secure protocols for evaluating a broad class of black box ``mixed-groups\u27\u27 circuits with bi-affine homomorphism, and new information-theoretic results. Finally, we uncover a striking structure underlying OLE: In particular, we show that OLE over GF(2n), is isomorphic to a group correlation over Z4n