Secret-Key Reconciliation by Public Discussion

Himanshu Tyagi, Shun Watanabe

Liu Sheng

This paper discusses how to distill the secret key by public discussion using unconditionally secure secret key agreement protocols. The relation between the length of the distilled secret key and the information reconciliation privacy amplification in the protocol is shown with the help of Universal Hash and Renyi entropy.

Keming Tian, Gang Xin, Jian Zhang

Qiuhua Wang, Xiaojun Wang, Qiuyun Lv +3 more

Abstract Generally, the information theoretically secret key agreement by public discussion consists of three phases, namely, advantage distillation, information reconciliation, and privacy amplification. In the existing literatures, these three phases are studied separately, and no comprehensive consideration has been given. In this paper, we analyze the restrictive relationship among these three phases from an overall point of view. For the satellite scenario, we analyze in detail the Winnow protocol for the first time. We also present the mutual restrictive relationship between the parameters of the advantage distillation phase and the information reconciliation phase. We further address how to set the parameters of the advantage distillation and the information reconciliation to maximize the total secret key agreement efficiency. Moreover, we determine the required length range of the initial random key string to guarantee the validation of the secret key agreement. Copyright © 2015 John Wiley & Sons, Ltd.

Takay Shimizu, Hisato Iwai, Hideichi Sasaoka

We consider information reconciliation in secret key agreement from a fading channel where two legitimate parties utilize channel estimates of their fading channel as correlated random variables to generate a secret key. The information reconciliation is a process of correcting the discrepancies between the legitimate parties' keys by public discussion in the presence of eavesdropper, where the amount of the information revealed in the public discussion is needed to be as little as possible. In this paper, we propose information reconciliation protocols using the reliability values of channel estimates in order to correct errors effectively. The proposed information reconciliation protocols are modified versions of a protocol used in quantum key distribution called sliced error correction using Cascade. Simulation results show that the proposed protocols can correct errors with less the number of disclosed bits and less the number of communications than the conventional sliced error correction using Cascade.

孝也 栃窪