A Quantum Physics Approach for Enabling Information-Theoretic Secure Communication Channels

Quantum communication, a field of applied quantum physics, is closely tied to quantum teleportation and quantum information processing, with a primary focus on leveraging the laws of quantum mechanics to secure communication systems. An intriguing application within this field is the protection of information channels from unauthorized eavesdropping through the implementation of quantum cryptography. Quantum key distribution (QKD) represents the most advanced and well-known application of quantum cryptography. QKD utilizes quantum mechanical effects for cryptographic tasks and breaking cryptographic systems. This study aims to explore the potential of employing quantum mechanics laws to enhance the security of communication systems. The QKD system operates on a simple principle, where two parties, Alice (the sender) and Bob (the receiver), utilize individual photons randomly polarized to represent bits 0 and 1, respectively. These photons are used to transmit a series of random numbers, serving as cryptographic keys. The parties are connected via classical and quantum channels, with Alice generating a random stream of qubits transmitted through the quantum channel. By performing classical operations over the classical channel, Alice and Bob verify if any eavesdropping attempts have occurred during qubit transfer. The presence of an eavesdropper is identified through the imperfect correlation between the two sets of bits obtained after qubit transmission. A vital aspect of robust encryption schemes is the utilization of true randomness, which can be easily generated using quantum optics. Quantum communication holds promising applications in diverse sectors, including banking, government, industry, and military domains. This research seeks to investigate the possibilities of leveraging quantum mechanics laws to fortify communication systems’ security.