Fig. 4
From: Experimental measurement-device-independent quantum digital signatures
MDI-QKD-mediated QDS. The signature is sent by Alice to Bob using an MDI-QKD setup, over an optical fibre with a total length of 50 km. The protocol is denoted “MDI-QKD\EP”, where “\EP” stands for “without error correction and privacy amplification”. QKD\EP is used to send a signature from Alice to Charlie, whereas full QKD is used to distribute keys between Bob and Charlie to allow for the symmetrisation step of QDS (see Supplementary Note 1). The QKD links are implemented with two 25-km reels of single-mode fibre
