Data encryption is gaining much attention these days from the research community and industry for transmitting secure information over access networks, i.e. 'fiber-to-the-home (FTTH)' networks and data centers. It is important that the newly designed encrypted networks are fully functional, reconfigurable, compatible, flexible and scalable with the existing deployed optical fiber networks around the globe. The prime benefit of having FTTH networks is the optical end-to-end data encryption that can best be implemented by quantum-keydistribution (QKD) protocols using state-of-the-art telecommunication components, i.e. continuous-variable quantum key distribution (CV-QKD). In this paper, we numerically investigate the quadrature phase shift keying (QPSK) based CV-QKD network that is compatible with the next generation (NG) services such as point-to-point (P2P) transmission and multicast overlay (MCO) traffic for audio/video signalling. We have further investigated the performance of quantum signals on multiuser fibers by emulating 7-, 12-and 19-core multi-core fibers (MCF). 100 Mbits/s secure key rates (SKRs) can be generated for inter-core crosstalk (XT) values of ≤-20 dB. These results and theoretical framework will allow the telecommunication industry to extend these scenarios not only to accommodate more complex trust constraints, but also to take into account the robustness and resiliency of a complex encrypted network.