An innovative quantum cryptography (QC) framework based on the tenets of quantum physics is laid forth in this research. The limits of eavesdropping detection, the inquiry centers on BB84 quantum key distribution approaches. The BB84 protocol’s careful balancing act between efficient use of resources and accurate detection of eavesdropping is brought to light by a study using Bernstein inequalities. A BB84 protocol and eavesdropping detection techniques are presented to deal with evolving quantum channel parameters. The protocols are more adaptable and resilient, with the flexibility to adjust the polarization basis for qubit evaluation and measurement approaches incorporating QBER and merged QBER. The study’s implementation shows impressive accuracy in eavesdropping detection, even in settings with constantly changing quantum channels, by executing the BB84 protocol with qubits on IBM’s Qiskit platform. Quantum cryptography theory and practical security protocols benefit significantly from this all-encompassing method, combining theoretical underpinnings with practical implementations.