中国密码学会2022年密码算法学术会议

ZUC-256 is a stream cipher designed for 5G applications by the ZUC team. Together with AES-256 and SNOW-V, it is currently being under evaluation for standardized algorithms in 5G mobile telecommunications by Security Algorithms Group of Experts (SAGE). In this talk, I will describe how to analyze the security of the ZUC initialization phase from the perspective of modular differences and signed differences. Our results indicate that 31 rounds of the old ZUC-256 initialization scheme and 30 rounds of the latest initialization scheme can be distinguished from a random permutation with a practical time complexity.