"Unbreakable Codes "Quantum Key Distribution System

[deakie]

yes but the cost.....darn....either that or there is a slight misleading in what they actually say.....me nuh trus dem iah...me nah seh te thing dun work....jus how it work..... ???
neva know we that advanced yet.....

if these devices be true, that will revolutionise the way i work or rather the instruments i use.....

[deakie]

let me expand on what i mean crypto...yu will see what im saying....

Its 730 m free-space link, which uses a stream of single photons

Although the transmission distances have steadily improved over the past few years, the current records are 150 km in fiber and 23 km in free space

This synchronized detection helps distinguish the QKD photons generated by a pair of 845 nm VCSELs from stray light such as photons from the Sun and thus raise the key transmission rate

a single photon travelling that distance in a fiber without absorption? think of the error rate due to absorbed photons...a fiber is not really a true mirror is it..

you distinguish a photon from the background photon?
absolutely no way....

it must be that its a bunch of photons. wave packets behaving as one.....

how do you transmit info in a single photon....i hate when they get their descriptions wrong.......i'll try to find this on nist.....

[deakie]

found it...both the nist reference and the actual paper if you are interested.....it does show its a burst pulse.....

http://www.nist.gov/public_affairs/r...uantumkeys.htm

http://www.opticsexpress.org/view_fi...%2BJ0%20%20%0A

second paragraph in introdcution section of the second link.....holds the clue to what they are actually saying....plebs...