The objective of the proposed research is to advance the engineering principles of quantum communication by investigating protocols under covertness and secrecy constraints. Despite significant theoretical and experimental progress, quantum engineering lacks intuitive frameworks comparable to classical systems. This thesis addresses that gap by analyzing phase-shift keying modulated two-mode squeezed vacuum states over bosonic channels and evaluating their performance relative to optimal limits. It further explores a covert communication protocol with effective entanglement consumption while preserving optimal rates. Future tasks include studying protocol robustness to non-i.i.d. phase TMSV source, extending analysis to round-trip entangled models, and developing security proofs for quantum memory-free secure direct communication.