Quantum key distribution (QKD) allows two parties to share an unconditionally secure secret key. Security is guaranteed by the laws of quantum mechanics, ensuring that the key can be used afterwards to encrypt and decrypt secret messages as a one-time pad. Quantum key distribution with continuous variables (CVQKD) has been proposed as an alternative to the most commonly implemented photon-counting quantum cryptography, and it offers the prospect of very high bit rate secure key distribution, which will be essential for practical quantum cryptography networks in the future. Furthermore, the compatibility of a QKD system with current telecommunication networks is essential for the general applicability of quantum cryptography. In this proposal, we are interested in implementing a practical and efficient CVQKD system fully integrated in a standard telecommunication network. To this end, we will be using well-established telecommunication technology in conjunction with new advances in reconciliation algorithms and security proofs related to continuous-variable QKD. The project outcome will be the first complete CVQKD prototype integrated in a quantum cryptography communication network and will open the way to real-life applications of the research on quantum information processing and communication.