A Capacity-achieving One-message Key Agreement With Finite Blocklength\n Analysis

Information-theoretic secret key agreement (SKA) protocols are a fundamental\ncryptographic primitive that are used to establish a shared secret key between\ntwo or more parties. In a two-party SKA in source model, Alice and Bob have\nsamples of two correlated variables, that are partially leaked to Eve, and\ntheir goal is to establish a shared secret key by communicating over a reliable\npublic channel. Eve must have no information about the established key. In this\npaper, we study the problem of one-message secret key agreement where the key\nis established by Alice sending a single message to Bob. We propose a\none-message SKA (OM-SKA) protocol, prove that it achieves the one-way secret\nkey capacity, and derive finite blocklength approximations of the achievable\nsecret key length. We compare our results with existing OM-SKAs and show the\nprotocol has a unique combination of desirable properties.\n