Secret key rate bounds for quantum key distribution with faulty active phase randomization Xoel Sixto, Guillermo Currás-Lorenzo, Kiyoshi Tamaki and Marcos Curty EPJ Quantum Technol., 10 1 (2023) 53 Published online: 15 December 2023 DOI: 10.1140/epjqt/s40507-023-00210-0