Quantum key distribution (QKD) uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the most well known example of the group of quantum cryptographic tasks.
An important and unique property of quantum key distribution is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented which detects eavesdropping. If the level of eavesdropping is below a certain threshold, a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about it), otherwise no secure key is possible and communication is aborted.
Wo oh oh
wo oh oh, wo oh oh oh
wo oh
Now baby I been thinking bout how you been acting strange
and baby I been thinking how so many things have changed
in my life, in my home, in my bed
said I remember how you used to love
How you used to love, you don't love no more
how you used to care, you don't care no more
that's alright, that's ok
drop the key on your way
catch a bus, ride the train
it doesn't matter just keep going
Now boy I can remember how I used to foot the bill
and yes I do regret the day I took your broke ass in
to my life, to my home, to my bed
said that I must have lost my head
I guess you thought that I'd let you walk on me like the floor
I gues you thought that you'd keep tracking dirt inside my door
you got it all wrong
it's been too long
all of the love is gone
now I'm singing you this song
How you used to love, you don't love no more
how you used to care, you don't care no more
that's alright, that's ok
drop the key on your way
grab a bus, ride the train
it doesn't matter just keep going
How you used to love, you don't love no more
how you used to care, you don't care no more
that's alright, that's ok
drop the keys on your way
grab a bus, ride the train
it doesn't matter just keep going
You must have thought that you were getting over for so long
but I was giving you the chance to make things right from being so wrong
but your time is up, took too long, I don't wanna hear it
get your shirt, shoes, pants and draws up from outta here
Oh oh oh oh
wo oh ooh wo
woo woo oh
Like you used to love, you don't love no more
how you used to care, you don't care no more
that's alright, that's ok
drop the keys on your way
grab a bus, ride the train
it doesn't matter just keep going
How you used to love, you don't love no more
how you used to care, you don't care no more
that's alright, that's ok
drop the keys on your way
grab a bus, ride the train
it doesn't matter just keep going
Oh oh oh