29 June 2018
| Alan Burkitt-Gray
Telefónica is planning to test the use of quantum key cryptography in metro networks where security is an issue.
The company has already carried out a field trial over
regular metro fibre in Madrid, but now wants to explore
practical uses of the highly secure technology.
Diego Lopez, the company’s head of technology
exploration and standards, told Capacity: "We
demonstrated that we can integrate quantum key cryptography
into our normal network services to enhance secure
Quantum physics will be used to distribute encryption keys over
the network, using ordinary traffic-carrying fibres –
not even dark fibres, said Lopez. "We think we will be able to
enhance the security of our current infrastructure."
For the Madrid trial, Telefónica used equipment from
Huawei’s research laboratories in Munich to
connect three nodes. "It was installed and connected by our
network operations people. The fibre and all the elements were
commercial. There was nothing special about them. We used a
half-rack of commercial servers."
The trial, which also involved the Universidad
Politécnica de Madrid (UPM), indicates that
Telefónica could deploy quantum key distribution (QKD)
on its regular network, said Lopez.
QKD uses one of the weirder features of quantum physics. First
described by Albert Einstein in 1935, quantum entanglement
means that pairs of particles are related even if they are
separated by a great distance. It was, Einstein is reputed to
have said, "spooky action at a distance".
Telefónica board member Juan-Ignacio Cirac, a physicist
who is a pioneer of quantum computing, said: "We can make a
random bit sequence to appear at one place and simultaneously
at another one, without making it pass in between. It is sort
of magic, but something that quantum physics predicts. It is a
way of exchanging secure keys that we have to make the most of,
since it cannot be hacked."
According to Lopez, QKD is "limited to 200-300km" at the
moment, "but at least this means you can run QKD services in
metro environments. This is something that we are working
This is still in the field of advanced research, said Lopez.
"We are planning the next steps. We want to test the
feasibility of a service … using industrialised devices
and software. I don’t think it would take much
time but this would be a decision of our commercial
Applications would be in "any kind of application that has an
interest in security", he told Capacity, including
hospitals, banks, police and security services. "After that,
almost anyone. We have demonstrated that it can be done at
reasonable cost. With software-defined networks (SDNs) we can
share fibre with other data. There is no limit to this."
He said that there are currently no standards for equipment or
software in the QKD field, but Telefónica is working
with the European Telecommunications Standards Institute (ETSI)
on unified applications programming interfaces (APIs).
"We are continuing research on the software layer and
integration," said Lopez. And it is also looking to test the
technology over more than the initial three nodes, perhaps
including "several potential users" in what he called a
"pre-commercial" stage. "We want to interconnect data centres
to data centres, and data centres to customers," he
Telefónica also wants to test the technology in its
Unica infrastructure programme for network functions
virtualisation (NFV), "to test securing the connections".