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.
In this article, we give an overview of current research on shared secret-key agreement between two parties. This agree⁃ ment is based on radio wireless channel characteristics. We discuss the advantages of this approach over traditional cryp⁃ tographic mechanisms and present the theoretical background of this approach. We then give a detailed description of the key-agreement process and the threat model, and we summarize the typical performance metrics for shared se⁃ cret-key agreement. There are four processes in shared secret-key agreement: sampling, quantization, information recon⁃ ciliation, and privacy amplification. We classify prior and current research in this area according to innovation on these four processes. We conclude with a discussion of existing challenges and directions for future work.
Information-theoretic secret key agreement (SKA) protocols are a fundamental cryptographic primitive that are used to establish a shared secret key between two or more parties. In a two-party SKA in source model, Alice and Bob have samples of two correlated variables, that are partially leaked to Eve, and their goal is to establish a shared secret key by communicating over a reliable public channel. Eve must have no information about the established key. In this paper, we study the problem of one-message secret key agreement where the key is established by Alice sending a single message to Bob. We propose a one-message SKA (OM-SKA) protocol, prove that it achieves the one-way secret key capacity, and derive finite blocklength approximations of the achievable secret key length. We compare our results with existing OM-SKAs and show the protocol has a unique combination of desirable properties.