Information-theoretically secure data origin authentication with quantum and classical resources
This addresses secure data origin authentication for cryptography, with a novel quantum-assisted approach that is incremental over classical limits.
The paper tackled the problem of whether quantum resources can improve information-theoretically secure message authentication over classical methods, showing that passive quantum schemes offer no advantage but an interactive entanglement-assisted scheme can authenticate messages with a key as long as the message.
In conventional cryptography, information-theoretically secure message authentication can be achieved by means of universal hash functions, and requires that the two legitimate users share a random secret key, which is twice as long as the message. We address the question as of whether quantum resources can offer any advantage over classical unconditionally secure message authentication codes. It is shown that passive prepare-and-measure quantum message-authentication schemes cannot do better than their classical counterparts. Subsequently we present an interactive entanglement-assisted scheme, which ideally allows for the authentication of classical messages with a classical key, which is as long as the message.