The “uncrackable codes” made by exploiting the branch of physics called quantum mechanics have been for the first time sent down kilometres of standard broadband fibre. [1] This “quantum key distribution” has until now needed a dedicated fibre separate from that used to carry data. Sending faint, delicate quantum keys required dedicated, so-called “dark fibres”, with no other light signals present. That was an inherently costly prospect for users who had to install or lease a separate fibre. But a new technique reported in Physical Review X shows how to unpick normal data streams from the much fainter, more delicate quantum signal. The quantum key distribution or QKD idea is based on the old idea of sharing of a key between two parties. Tiny, faint pulses of laser light are used in a bid to make single photons with a given alignment, or polarisation. Two different polarisations can act like the 0s and 1s of normal digital data, forming a means to share a cryptographic key. What makes it secure is that once single photons have been observed, they are irrevocably changed. An eavesdropper trying to intercept the key would be found out.
Philosophers have postulated the idea of us affecting (and creating) what we call “Reality” for thousands of years. Ideas like that sounded weird (at best) and were discarded by mainstream philosophers and common people who where afraid to see anything beyond their nose. Now we have surpassed the point of discussion and have directly reached to the point of solid everyday applications of that “weird” concept… Thank you technology!
No matter how illogical it may sound, remember in the near future that your data is protected by that very “illogical” thing…
