Quantum digital signatures (QDSs) utilize shared keys generated by quantum key distribution, thereby providing information-theoretic security. Most existing QDS schemes, however, only support single-signer scenarios, which limits their applications in large-scale quantum networks. Based on previous studies of multisigner QDSs, we design and experimentally demonstrate a scalable multisigner QDS system. The results show that the designed system enables multiple signers to jointly sign the same message while supporting receiver verification and arbitrated validation. The single-photon count rate used in the experiment was approximately $2.6\times {10}^4$ counts/s. The measured coincidence-to-accidental ratio (CAR) was greater than 830, and the second-order correlation function $g^{\left(2\right)}\left(0\right)$ was less than 0.01. The two-photon interference visibility measured for the polarization-entangled state $|{\mathrm{\Phi }}^{+}\rangle =\left(\right|HH\rangle +|VV\rangle )/\sqrt{2}$ was approximately 99.01%, corresponding to a quantum bit error rate below 0.495%. This work demonstrates a reliable implementation of multisigner QDSs and may provide a practical approach to secure authentication and collaborative authorization in future large-scale quantum networks.

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• Quantum communication
• Quantum cryptography
• Quantum networks