Conference key agreement with single-photon interference

Understand

The intense research activity on Twin-Field (TF) quantum key distribution (QKD) is motivated by the fact that two users can establish a secret key by relying on single-photon interference in an untrusted node.

• Thanks to this feature, variants of the protocol have been proven to beat the point-to-point private capacity of a lossy quantum channel.
• Here we generalize the main idea of the TF-QKD protocol introduced by Curty et al.
• to the multipartite scenario, by devising a conference key agreement (CKA) where the users simultaneously distill a secret conference key through single-photon interference.