Improved guess-and-determine and distinguishing attacks on SNOW-V

In this paper, we investigate the security of SNOW-V, demonstrating two guess-and-determine (GnD) attacks against full version with complexities 2384 and 2378, respectively, one distinguishing attack a reduced variant complexity 2303. Our GnD use enumeration recursion to explore valid guessing paths, try truncate as many invalid paths possible at early stages by carefully designing order guessing. our first attack, guess three 128-bit state variables, determine remaining four according consecutive keystream words. We finally next words verify correct guess. The second is similar but exploits more word side information helping paths. targets where 32-bit adders are replaced exclusive-OR operations. samples can be collected from short sequences under different (key, IV) pairs. These do not threaten provide in-depth details for understanding its give new ideas cryptanalysis other ciphers.