Error-tolerant oblivious transfer in the noisy-storage model

TL;DR

This paper explores the security of oblivious transfer in quantum cryptography under noisy and lossy conditions, providing bounds that account for both trusted and untrusted noise sources.

Contribution

It introduces tight security bounds for oblivious transfer considering trusted and untrusted noise using entropic uncertainty relations.

Findings

Security bounds derived for noisy and lossy quantum storage

Analysis of independent and correlated noise effects

Enhanced understanding of error correction impact on security

Abstract

The noisy-storage model of quantum cryptography allows for information-theoretically secure two-party computation based on the assumption that a cheating user has at most access to an imperfect, noisy quantum memory, whereas the honest users do not need a quantum memory at all. In general, the more noisy the quantum memory of the cheating user, the more secure the implementation of oblivious transfer, which is a primitive that allows universal secure two-party and multi-party computation. For experimental implementations of oblivious transfer, one has to consider that also the devices held by the honest users are lossy and noisy, and error correction needs to be applied to correct these trusted errors. The latter are expected to reduce the security of the protocol, since a cheating user may hide themselves in the trusted noise. Here we leverage entropic uncertainty relations to derive tight bounds on the security of oblivious transfer with a trusted and untrusted noise. In particular, we discuss noisy storage and bounded storage, with independent and correlated noise.