A Permutation Dispatch Circuit Design for Quantum Permutation Pad Symmetric Encryption

Quantum Permutation Pad (QPP) is a symmetric-key quantum block data encryption scheme. Central to QPP is using value permutations in the encryption and decryption procedures. A plaintext is encrypted with a sequence of randomly selected permutations and decrypted by their inverses. Implementing QPP requires a random dispatching operation determining the permutation operators used for encryption. The efficient implementation of the dispatching operation remains an open question. We propose an efficient solution to the dispatching operation. A detailed circuit design is presented, analyzed, and implemented.