Advanced Encryption Standard on a Quantum System

Quantum computers have shown their capability to outperform the world's fastest supercomputers despite their nascent stage. This poses questions about the security of existing encryption schemes and offers exciting new possibilities to the field of cryptography. Extension of existing cryptographic algorithms and development of novel cryptographic protocols exploiting the physics of the quantum realm are unique prospects for the industry moving forward. This work implemented a hybrid classical-quantum AES-128 circuit on the open-source Qiskit simulator and explored the possibilities of reducing the qubit count necessary for implementing the same. Multiple classical bits were encoded into a single qubit for processing, and a machine learning model was trained to decode the output data back to classical bits. The circuit size was halved by changing the encoding form of classical bits into qubits. Our hybrid circuit also achieved significant speed up over the existing hybrid circuit for AES encryption and decryption.