AsianScientist (Mar. 27, 2014) – The way we secure digital transactions could soon change, say researchers who are using quantum cryptography to enhance the safety of online communications.
The work, published in Nature Communications, is a collaboration between National University of Singapore’s Center for Quantum Technologies (CQT) and University of Waterloo’s Institute for Quantum Computing (IQC).
“Having quantum cryptography to hand is a realistic prospect, I think. 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,” says Stephanie Wehner, a Principal Investigator at CQT and co-author of the research.
In cryptography, the problem of providing a secure way for two mutually distrustful parties to interact is known as “two-party secure computation.” Addressing this problem requires mathematical methods of data encryption and decryption; these methods are referred to as cryptographic schemes.
To demonstrate the effectiveness of their proposed method, CQT theorists Wehner and Nelly Ng teamed up with colleagues to deploy 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).
Unlike protocols for ROT that use only classical physics, the security of the quantum protocol cannot be broken by computational power. Its security depends only on Alice and Bob not being able to store much quantum information for too long. This is a reasonable physical assumption, given today’s best quantum memories are able to store information for minutes at most.
“Oblivious transfer is a basic building block that you can stack together, like Lego, to make something more fantastic,” says Wehner.
The article can be found at: Erven et al. (2014) An experimental implementation of oblivious transfer in the noisy storage model.
Source: Center for Quantum Technologies; Photo: phsymyst/Flickr/CC.
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