Quantum Cryptography with Macroscopic Photon-Number-Correlated Light
Michael G. Raymer, Andrew Funk · Acta Physica Polonica A · 2002
W e descri be a new scheme for perf ormin g quan tum key distributi on .W e present tw o physica l implementations for the quantum key distribu tio n system.T he Ùrst implementation uses a typ e-I I optical-parametri c ampliÙer to generate the optical pulses w hich contain the key inf ormation.T he second implementation uses correlated semicondu ctor emitters to generate the optical pulses.PAC S numb ers: 03.67.Dd , 03. 67.H k, 42.50.D v, 42.50.Lc 1 .I n t r o d u ct i on : qu an t u m st at es p r o vi d e secu r i t y Let us consider the fol l owing scenari o: one p erson (Al i ce) wa nts to send a secret m essage to a second p erson ( Bo b).At the sam e ti me, an eavesdropp er (Eve) i s attem pti ng to obta i n the secret m essage.Al i ce and Bo b can use a One-Ti me Pa d crypto gra phi c pro to col in order to securely tra nsm i t thei r secret m essage.Thi s pro to col consists of Al i ce and Bo b ha vi ng a shared secret key pri or to the sending of the secret m essage.The key wi ll consi st of a stri ng of ra ndo m bi nary da ta .The key i s used to encode the secret m essage by a sim pl e bi nary addi ti on of the secret m essage wi th the key .The encoded secret message can then b e tra nsm i tted over a publ i c channel (i .e. a channel whi ch can b e seen by any one i ncl udi ng Eve).As l ong as the key data i s shared by onl y Al i ce and Bo b and the key i s onl y used once, i t i s pro vabl y i m p ossibl e for Eve to decode the encoded m essage.Thi s wo ul d app ear to b e a very p owerful techni que for sending secret messages.The catch i s tha t i t i s ha rd to create and di stri bute a key tha t i s shared by Al i ce and Bo b but al so rem ai ns secret after the di stri buti on pro cedure.Presum -Ê corr esp on din g au t h o r; e-m ail : ray me r@ore gon .uor ego n. edu (4 37)