  All kinds of device loopholes give rise to a great obstacle to practical
secure quantum key distribution (QKD). In this article, inspired by the
original side-channel-secure protocol [Physical Review Applied 12, 054034
(2019)], a new QKD protocol called phase-coding side-channel-secure (PC-SCS)
protocol is proposed. This protocol can be immune to all uncorrelated side
channels of the source part and all loopholes of the measurement side. A
finite-key security analysis against coherent attack of the new protocol is
given. The proposed protocol only requires modulation of two phases, which can
avoid the challenge of preparing perfect vacuum states. Numerical simulation
shows that a practical transmission distance of 300 km can be realized by the
PC-SCS protocol.
