Healthcare data growth at an exponential rate together with rising cyber threats require sophisticated cryptographic systems to protect Electronic Health Records (EHRs) from unauthorized access and data tampering. The research develops a cryptographic system which uses simulated quantum key distribution through the E91 protocol to generate symmetric encryption keys that is encrypted using Advanced Encryption Standard (AES) in Cipher Block Chaining (CBC) mode to protect healthcare data. The system operates by using IBM Qiskit’s AerSimulator backend to create entangled qubit pairs for deriving a quantum-safe key between two communicating parties. The entropy measurement of the generated key approaches the maximum value of randomness which provides effective protection against brute-force attacks. The AES encryption process using achieves rate of approximately 6.58 MB/s during encryption operations and 9.34 MB/s during decryption operations. The proposed method demonstrates efficient computation and deployment potential for healthcare applications with limited resources including edge-based IoT medical devices and federated learning systems. Security analyses show that this approach gives a good protection against both classical attackers and near-term quantum attackers. The research shows how post-quantum cryptographic methods can be practically used to protect future healthcare systems.