Because of the substantial progress in quantum computing technology, the safety of traditional cryptologic schemes is facing serious challenges. In this study, we explore the quantum safety of the lightweight cipher MIBS and propose quantum key-recovery attacks on the MIBS cipher by utilizing Grover’s algorithm and Bernstein–Vazirani algorithm. We first construct linear-structure functions based on the 5-round MIBS cipher according to the characteristics of the linear transformations, and then we obtain a quantum distinguisher of the 5-round MIBS cipher by applying Bernstein–Vazirani algorithm to the constructed functions. Finally, utilizing this distinguisher and Grover’s algorithm, we realize a 7-round key-recovery attack on the MIBS cipher, and then we expand the attack to more rounds of MIBS based on a similar idea. The quantum attack on the 7-round MIBS requires 156 qubits and has a time complexity of $2^{10.5}$. An 8-round attack requires 179 qubits and has a time complexity of $2^{22}$. Compared with existing quantum attacks, our attacks have better time complexity when attacking the same number of rounds.

SM4, as a block cipher standard in China, has received extensive attention since the date of its publication. Its implementation correctness and security have rapidly become a research hotspot. With the popularity of cryptographic algorithms in network security, attack methods such as key whitening attack, software static analysis, and reverse engineering in the software implementation environment are also constantly developing. In order to resist these attack methods, a white-box implementation of the key in the cryptographic algorithm is required. Common white-box implementation schemes add a large number of linear or nonlinear transformations, which greatly reduces the implementation efficiency while enhancing the security. In this paper, we optimized the white-box design method of Xiao-Lai SM4 algorithm. According to its structural characteristics, we reduced one affine transformation and increased nonlinear encoding without disclosing the relevant information of intermediate data. Also, our work distinguished the implementation of the first, intermediate and last rounds. We operated the simulation implementation, and the implementation efficiency is significantly improved. Then the white-box diversity and white-box ambiguity in the optimized scheme are calculated, which proves the security of the optimized algorithm. After the correctness and implementation efficiency tests, the encryption speed is improved by 18.6% and the decryption speed is improved by 20.8% compared with the original scheme.

Due to the superiority of quantum computing, traditional cryptography is facing a severe threat. This makes the security evaluation of cryptographic systems in quantum attack models both significant and urgent. For symmetric ciphers, the security analysis heavily relies on cryptanalysis tools. Thus, exploring the use of quantum algorithms in traditional cryptanalysis tools has garnered considerable attention. In this study, we utilize quantum algorithms to improve impossible differential attacks and design two quantum automated tools to search for impossible differentials. The proposed quantum algorithms exploit the idea of miss-in-the-middle and the properties of truncated differentials. We rigorously prove their validity and calculate the quantum resources required for their implementation. Compared to the existing classical automated cryptanalysis, the proposed quantum tools have the advantage of accurately characterizing S-boxes while only requiring polynomial complexity, and can take into consideration the impact of the key schedules in a single-key model.

SAILFISH-I, first proposed by Agarwal et al. in 2022, is a lightweight block cipher with a typical Feistel structure, which is evaluated for the first time in this paper for its resistance to integral cryptanalysis. Firstly, the S-box and the overall structure are modeled based on the MILP method. We can find 11-round integral distinguishers for SAILFISH-I, which further reduces the number of active bits to find 10-round integral distinguishers with 57 active bits. Secondly, one round is added in front of the distinguisher and three rounds are added at the back, while the partial sum technique is used for the first time to recover the key of SAILFISH-I for 14-round. In the whole process of integral attack, the required data complexity is adding one round in front of the distinguisher and three rounds at the same time, using the partial sum technique. For the key recovery of SAILFISH-I for the first time, the required data complexity is $$2^{59}$$ 2 59 chosen plaintexts, the time complexity is $$2^{59.42}$$ 2 59.42 times 14-round of encryption, and the memory complexity is $$2^{57}$$ 2 57 . Finally, based on the 14-round key recovery attack, the guessing order of key bits is optimized, and the 18-round key recovery attack on SAILFISH-I is completed for the first time. Throughout the integral attack process, we recover 97 bits of key with $$2^{61.64}$$ 2 61.64 chosen plaintexts and $$2^{147.06}$$ 2 147.06 time complexity of the 18-round encryption. Moreover, if we can use the balanced bits fully, then the number of recoverable key bits will rise to 129.

The Feistel structure represents a fundamental architectural component within the domain of symmetric cryptographic algorithms, with a substantial body of research conducted within the context of classical computing environments. Nevertheless, research into specific symmetric cryptographic algorithms utilizing the Feistel structure is relatively scarce in quantum computing environments. This paper, for the first time, proposes a five-round distinguisher for Camellia under the quantum chosen-ciphertext attack (qCCA) setting, with its effectiveness empirically validated. Additionally, by combining Grover’s algorithm and Simon’s algorithm, we construct a nine-round key-recovery attack model against Camellia. Through an in-depth analysis of Camellia’s key expansion algorithm, we significantly reduce the complexity of the key-recovery attack. The proposed attack achieves a time complexity of 2^61.5 for recovering the correct key bits and requires 531 quantum bits.