When quantum computers are fully developed, they will break much of today's encryption whose security is only based on mathematical assumptions. Technology Briefing
Transcript
Humanity
is locked in a "technology arms race" of sorts. When quantum computers are
fully developed, they will break much of today's encryption whose security is
only based on mathematical assumptions. To pre-emptively address this,
scientists are working on new ways of communicating through large networks that
don't rely on assumptions, but instead use the quantum laws of physics to
ensure security. That means those laws of nature would need to be broken
to hack the encryption.
According
to a recent study by University College London, Oxford University and the
University of Edinburgh published in Physical
Review Letters, a new way of communicating securely between
three or more quantum devices, irrespective of who built them, has been
developed.
This approach
works for a general network because users don't need to trust the manufacturer
of the device or network for secrecy to be guaranteed. This method works
by using the network's structure to limit what an eavesdropper can learn.
The
approach bridges the gap between the theoretical promise of perfect security
guaranteed by the laws of quantum physics and the practical implementation of
such security in large networks.
It tests
the security of the quantum devices prior to engaging in communications with
the whole network. It does this by checking if the correlations between
devices in the network are intrinsically quantum and cannot have been created
by another means.
These
correlations are used to establish secret keys which can be used to encrypt any
desired communication. Security is ensured by the unique property that
quantum correlations can only be shared between the devices that created them,
ensuring no hacker can ever come to learn the key.
The team
used two methods - machine learning and causal inference - to develop the test
for the un-hackable communications system. This approach distributes
secret keys in a way that cannot be effectively intercepted, because through
quantum mechanics their secrecy can be tested and guaranteed.
This work
can be thought of as creating the software that will run on hardware currently
being built to realize the potential of quantum communications. In future
work, the team would like to work with partners in the UK national quantum
technologies program to develop it further. They hope to extensively prove the
quantum network approach over the next few years.
The team
acknowledge that an un-hackable network could be abused in the same way that
current networks are but highlight that there is also a benefit for ensuring
privacy.
