Figure 12

The decryption for functional currently-realizable implementation of a 2-qubits QPP on IBMQ using Qiskit acts on the 2-bit ciphertext blocks. For each such block, a new quantum circuit is created with qubits initialized to the ciphertext block bits. Ciphertext qubits are the decrypted using Inverse QPP and the resulting state is measured. The measurement results are precisely the blocks of the randomized plaintext. The decryption party then applied classical XOR opertaor using the same shared key as the encryption party to produce the original plaintext