A CV-QKD system comprising a plurality of transmitters, one or more splitters, and a plurality of receivers is provided. Each transmitter modulates a quantum signal according to a discrete or continuous distribution in phase and amplitude. Each splitter distributes N modulated quantum signals, received from a respective transmitter or from another splitter, into M modulated quantum sub-signals. Each receiver is configured to: receive, via a respective quantum channel, a modulated quantum sub-signal associated to one or more of the transmitters from the one or more splitters; detect one or more quadrature components of the received modulated quantum sub-signal; and perform a respective post-processing protocol with one or more of the plurality of transmitters to generate one or more individual final secret keys between the one or more transmitters and the receiver and/or one or more common secret keys between the one or more transmitters and the plurality of receivers.