Experimental quantum secure network with digital signatures and encryption

Abstract

Abstract Cryptography promises four information security objectives, namely, confidentiality, integrity, authenticity, and non-repudiation, to support trillions of transactions annually in digital economy. Efficient digital signatures, ensuring integrity, authenticity, and non-repudiation of data with information-theoretical security are highly urgent and intractable open problems in cryptography. Here, we propose a high-efficiency quantum digital signature (QDS) protocol using asymmetric quantum keys acquired via secret sharing, one-time universal2 hashing, and one-time pad. We just need to use a 384-bit key to sign documents of up to 264 lengths with a security bound of 10−19. If one-megabit document is signed, the signature efficiency is improved by more than 108 times compared with previous QDS protocols. Furthermore, we build the first all-in-one quantum secure network integrating information-theoretically secure communication, digital signatures, secret sharing, and conference key agreement and experimentally demonstrate this signature efficiency advantage. Our work completes the cryptography toolbox of the four information security objectives.