This paper presents a quantum key distribution (QKD) protocol based on the transmission of gaussian-modulated coherent states and shot-noise-limited homodyne detection. The protocol does not require squeezed or entangled beams and achieves complete secret key extraction using a reverse reconciliation technique followed by privacy amplification. The security of the protocol is demonstrated to be secure for any line transmission, against gaussian individual attacks based on entanglement and quantum memories. The experimental setup and results show a net key transmission rate of about 1.7 megabits per second for a loss-free line and 75 kilobits per second for a line with 3.1 dB loss. The authors discuss the limitations of the current implementation, which are primarily technical, and highlight the potential for significant improvements in hardware and software. The paper also explores the relationship between cryptographic security and entanglement, showing that the protocol's security is closely related to entanglement, even though it does not explicitly use entangled states.This paper presents a quantum key distribution (QKD) protocol based on the transmission of gaussian-modulated coherent states and shot-noise-limited homodyne detection. The protocol does not require squeezed or entangled beams and achieves complete secret key extraction using a reverse reconciliation technique followed by privacy amplification. The security of the protocol is demonstrated to be secure for any line transmission, against gaussian individual attacks based on entanglement and quantum memories. The experimental setup and results show a net key transmission rate of about 1.7 megabits per second for a loss-free line and 75 kilobits per second for a line with 3.1 dB loss. The authors discuss the limitations of the current implementation, which are primarily technical, and highlight the potential for significant improvements in hardware and software. The paper also explores the relationship between cryptographic security and entanglement, showing that the protocol's security is closely related to entanglement, even though it does not explicitly use entangled states.