Scientists say they are a step closer to developing a secure internet after unveiling a prototype of what they believe is the largest quantum communication network of its kind.
Writing in the journal Science, they say it can simultaneously connect at least eight users across 17 kilometres while avoiding the risks and hardware requirements inherent in previous designs.
It has a range wide enough to serve as a city-wide system, says lead author Siddarth Joshi from the University of Bristol, UK, with simulations showing its architecture can be extended to 32 users.
Secure quantum networks require “keys” to decode transmitted data. If hackers intervene hacker, signs of interference occur, with errors created in what is received by the legitimate parties.
To scale this technology beyond two users, many networks rely on “trusted nodes”, which have access to the key information. This compromises security, however, and is costly, which has