Variational quantum attacks threaten advanced encryption standard based symmetric cryptography

We propose a variational quantum attack algorithm (VQAA) for classical advanced encryption standard (AES)-like symmetric cryptography, as exemplified by the simplified-data (S-DES). In VQAA, known ciphertext is encoded ground state of Hamiltonian that constructed through regular graph, and can be found using approach. designed ansatz cost function S-DES’s attack. It surprising sometimes VQAA even faster than Grover’s demonstrated our simulation results. The relationships entanglement entropy, concurrence, are investigated, which indicate plays crucial role in speedup.