|| Second-Order Asymptotics for One-way Secret Key Agreement
||Alireza Poostindouz, Reihaneh Safavi-Naini, University of Calgary, Canada|
||D3-S4-T4: Key Generation & Agreement I
||Wednesday, 14 July, 23:00 - 23:20
||Wednesday, 14 July, 23:20 - 23:40
Secret key agreement (SKA) is a basic cryptographic primitive that establishes a shared secret key between parties. In the two-party source model of SKA, Alice and Bob want to share a secret key. They each have private samples of two correlated variables that are partially leaked to Eve. In a one-way SKA protocol, Alice sends a single message to Bob over a public channel, allowing the two parties to calculate a shared secret key that will be essentially unknown to Eve. The length of the key is a function of the number of samples $n$. In this paper, we prove a tight second-order asymptotic approximation of the key length of one-way SKA protocols, and propose an approach to construct a computationally efficient one-way SKA protocol with near-optimum finite key length. We compare our results with related work, and discuss future research directions.