In the original definitions of information-theoretic secret-key agreement, the required secrecy condition was too weak. We show, by a generic reduction, that it can be strengthened without any effect on the achievable key-generation rate.
One big problem of the communication between two parties is the secrecy. That means how\nmuch information a third party can obtain by intercepting the messages transmitted from\none honest party to the other one. Therefore cryptography offers a wide range of protocols\nto ensure security with assumptions on the eavesdropper. So one was looking for an\ninformation-theoretical description of the scenario to get unconditional secure communication.\nIn this scenario we are considering two honest parties that want to communicate over\nan authenticated channel that the eavesdropper is wiretapping. This scenario introduced the definition of the intrinsic information and the secret-key rate which are a measure of the secrecy in this setting. Later because of strong analogies to quantum mechanics it turned out that this description was lacking a phenomena called bound information which is the disability of a probability distribution to create a secret-key even though it has predicted secrecy.\nNearly ten years of research have shown the existence of bound information for the multipartite case where several parties are communicating but not yet for the bipartite case.\nHence the approach of non-distillability seems a very promising one to find this conjecture.\nMotivated by this the approach we implemented this tool and simulated some distributions that have conjectured bound information. Thereby we improved the tool to reduce its calculationtime and to get closer to the aim.
In this paper, we study key-agreement which realizes the protection against key-exposure problems in the information-theoretic security setting. And we newly define a model and security notions for information-theoretically secure key-insulated key-agreement (KI-KA for short). In addition, we show tight lower bounds of sizes of entities' secret-keys required for KI-KA. We also propose constructions of KI-KA which are provably secure and optimal. Furthermore, we provide some applications of KI-KA.