Abstract
Cryptography promises four information security objectives, namely, confidentiality, integrity, authenticity, and non-repudiation, to support trillions of transactions annually in the digital economy. Efficient digital signatures, ensuring the integrity, authenticity, and non-repudiation of data with information-theoretical security are highly urgent and intractable open problems in cryptography. Here, we propose a protocol of high-efficiency quantum digital signatures using secret sharing, one-time universal₂ hashing, and the 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 quantum digital signature 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.