A team including researchers from the University of Waterloo says it has demonstrated a form of quantum cryptography that might be able to improve IT security on networks or bank ATMs.
“I expect that quantum technologies will gradually become integrated with existing devices such as smartphones, allowing us to do things like identify ourselves securely or generate encryption keys,” Stephanie Wehner, a principal investigator at the Centre for Quantum Technologies (CQT) at the National University of Singapore, and co-author of a just published paper on the work.
CQT theorists Wehner and Nelly Ng teamed up with researchers at the Institute for Quantum Computing (IQC) at the University of Waterloo for the demonstration with involved entangled photons.
There is no word on how or when this concept could be commercialized. But the Canadians are positive.
“Research partnerships such as this one between IQC and CQT are critical in moving the field forward,” Raymond Laflamme, executive director of the Institute for Quantum Computing, said in a statement. “The infrastructure that we’ve built here at IQC is enabling exciting progress on quantum technologies.
Here’s how the release described their work: The experiments performed at IQC deployed quantum-entangled photons in such a way that one party, dubbed Alice, could share information with a second party, dubbed Bob, while meeting stringent restrictions. Specifically, Alice has two sets of information. Bob requests access to one or the other, and Alice must be able to send it to him without knowing which set he’s asked for. Bob must also learn nothing about the unrequested set. This is a protocol known as 1-2 random oblivious transfer (ROT).
ROT is a starting point for more complicated schemes that have applications, for example, in secure identification.
Today, taking money out of an ATM requires that you put in a card and type in your PIN. You trust the bank’s machine with your personal data. But what if you don’t trust the machine? You might instead type your PIN into your trusted phone, then let your phone do secure quantum identification with the ATM, say the researchers.
Ultimately, the aim is to implement a scheme that can check if your account number and PIN matches the bank’s records without either you or the bank having to disclose the login details to each other
Unlike protocols for ROT that use only classical physics, the security of the quantum protocol cannot be broken by computational power, say the researchers. Even if the attacker had a quantum computer, the protocol would remain secure.
The release said the experiment adapted devices built to do a more standard form of quantum cryptography known as quantum key distribution (QKD), a scheme that generates random numbers for scrambling communication. Devices for QKD are already commercially available, and miniaturised versions of this experiment are in principle possible using integrated optics.
In the future, people might carry hand-held quantum devices that can perform this kind of feat, said the release.