Quantum computing is generally considered non-threatening to symmetric ciphers. Quantum attacks on symmetric ciphers require a thorough analysis of their internal structures, posing considerable difficulties and challenges. As of 2023, Google’s quantum supremacy chip, Sycamore, is still incapable of cryptanalysis. Leveraging D-Wave’s quantum annealing exploits the unique quantum tunneling effect, providing an edge in solving combinatorial optimization problems. It can be regarded as a class of artificial intelligence algorithm that can achieve global optimization. We propose a quantum heuristic symmetric cipher attack algorithm for substitution-permutation network (SPN) symmetric ciphers, which transforms the plaintext-ciphertext propagation rules within SPN structure into the problem of solving a constrained quadratic model (CQM). A novel reduction algorithm is employed to eliminate redundant constraint conditions. The D-Wave Advantage quantum computer is used to recover the encryption sub-keys. Using the quantum approximate optimization algorithm, IBM Q Experience can only recover two rounds of the Heys Cipher sub-key, whereas D-Wave Advantage achieves complete key recovery, validating its potential in quantum symmetric cipher attacks.

Integer factorization, the core of the Rivest−Shamir−Adleman (RSA) attack, is an exciting but formidable challenge. As of this year, a group of researchers’ latest quantum supremacy chip remains unavailable for cryptanalysis. Quantum annealing (QA) has a unique quantum tunneling advantage, which can escape local extremum in the exponential solution space, finding the global optimal solution with a higher probability. Consequently, we consider it an effective method for attacking cryptography. According to Origin Quantum Computing, QA computers are able to factor numbers several orders of magnitude larger than universal quantum computers. We try to transform the integer factorization problem in RSA attacks into a combinatorial optimization problem by using the QA algorithm of D-Wave quantum computer, and attack RSA-2048 which is composed of a class of special integers. The experiment factored this class of integers of size 2²⁰⁴⁸, N=p×q. As an example, the article gives the results of 10 RSA-2048 attacks in the appendix. This marks the first successful factorization of RSA-2048 by D-Wave quantum computer, regardless of employing mathematical or quantum techniques, despite dealing with special integers, exceeding 2¹⁰⁶¹−1 of California State University. This experiment verifies that the QA algorithm based on D-Wave is an effective method to attack RSA.