Secret key exchange in ultralong lasers by radiofrequency spectrum coding  

作　　者：Alessandro Tonello Alain Barthelemy Katarzyna Krupa Vincent Kermene Agnes Desfarges-Berthelemot Badr Mohamed Shalaby Sonia Boscolo Sergei K Turitsyn Juan Diego Ania-Castanon 

机构地区：[1]Universite de Limoges,XLIM,UMR CNRS 7252,123 Avenue A.Thomas,87060 Limoges,France [2]Physics Department,Faculty of Science,Tanta University,Tanta,Egypt [3]Aston Institute of Photonic Technologies,Aston University,Birmingham B47ET,UK [4]Instituto de Optica,CSIC,C/Serrano 121,Madrid 28006,Spain

出　　处：《Light(Science & Applications)》2015年第1期400-404,共5页光（科学与应用)（英文版）

基　　金：This work was supported by the French National Research Agency(grants LABEX SIGMALIM and ANR 08-JCJC-0122 PARADHOQS);the European Research Council(project ULTRALASER);the Leverhulme Trust(grant RPG-278);the Spanish MICINN project TEC2011-27314(RAMAS);We also acknowledge support by the XLIM Institute(grant VIP2013).

摘　　要：We propose a new approach to the generation of an alphabet for secret key exchange relying on small variations in the cavity length of an ultralong fiber laser.This new concept is supported by experimental results showing how the radiofrequency spectrum of the laser can be exploited as a carrier to exchange information.The test bench for our proof of principle is a 50-km-long fiber laser linking two users,Alice and Bob,where each user can randomly add an extra 1-km-long segment of fiber.The choice of laser length is driven by two independent random binary values,which makes such length become itself a random variable.The security of key exchange is ensured whenever the two independent random choices lead to the same laser length and,hence,to the same free spectral range.

关 键 词：fiber lasers fiber optics communications optical security and encryption 

分 类 号：TN2[电子电信—物理电子学]