Here we introduce an improved approach to Variational Quantum Attack Algorithms (VQAA) on crytographic protocols. Our methods provide robust quantum attacks to well-known cryptographic algorithms, more efficiently and with remarkably fewer qubits than previous approaches. We implement simulations of our attacks for symmetric-key protocols such as S-DES, S-AES and Blowfish. For instance, we show how our attack allows a classical simulation of a small 8-qubit quantum computer to find the secret key of one 32-bit Blowfish instance with 24 times fewer number of iterations than a brute-force attack. Our work also shows improvements in attack success rates for lightweight ciphers such as S-DES and S-AES. Further applications beyond symmetric-key cryptography are also discussed, including asymmetric-key protocols and hash functions. In addition, we also comment on potential future improvements of our methods. Our results bring one step closer assessing the vulnerability of large-size classical cryptographic protocols with Noisy Intermediate-Scale Quantum (NISQ) devices, and set the stage for future research in quantum cybersecurity.

改进的变分量子攻击算法 (VQAA) 提供了针对众所周知的加密算法的强大的量子攻击方法，效率更高，所需量子位数明显较少。我们对对称密钥协议（如S-DES，S-AES和Blowfish）的攻击进行了模拟，结果表明我们的攻击允许一个小型8量子比特量子计算机在24次迭代次数更少的情况下，通过经典模拟找到一个32比特Blowfish实例的秘密密钥。我们的工作还展示了轻量级密码（如S-DES和S-AES）的攻击成功率的改进。此外，我们还讨论了超过对称密钥密码学的应用，包括非对称密钥协议和哈希函数。我们的结果使得使用嘈杂中间规模量子（NISQ）设备评估大型经典加密协议的易受攻击性更加接近，并为量子网络安全性的未来研究奠定了基础。

使用高级变分量子攻击破解密码协议