A One-Round Key Agreement Protocol with Information-Theoretic Security
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Information-theoretic secure key agreement protocols do not use computational assumptions and will stay secure with future advances in computing technologies. We consider a setting where Alice and Bob have access to correlated variables, and use a public channel to interact and obtain a shared secret key. Efficiency of protocols in this setting is measured by the secret key rate which is asymptotically upper bounded by the secret key capacity of the setting. Recently a tight bound for key rate in finite length regime was derived and an optimal protocol that achieves the asymptotic and finite length bounds was proposed. The protocol, however, requires many rounds of interactions. In this paper, we propose a noninteractive protocol with optimal asymptotic and near-optimal finite length performance. We prove security and efficiency of the protocol and give a modified version of the protocol that significantly improves computation cost of the parties by sacrificing some of the key rate. We show how this trade-off is achievable by controlling the parameters of the system.
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