# Random cipher ## Script: ```python from random import randint from z3 import * def decrypt(text): key = randint(1, 2 * len(text)) result = [] for c in text: x = Int('x') s = Solver() s.add(c - (x % key) == x) if s.check() == sat: model = s.model() result.append(model[x].as_long()) key = key + 1 return result if __name__ == '__main__': a = [200,202,204,64,202,220,198,228,242,224,232,80,232,202,240,232,82,116,64,70,64,204,216,194,206,64,210,230,116,64,206,228,222,200,220,222,246,240,194,90,240,194,90,240,194,90,232,202,228,228,222,228,210,230,232,250,20,64,64,64,64,214,202,242,64,122,64,228,194,220,200,210,220,232,80,98,88,64,100,64,84,64,216,202,220,80,232,202,240,232,82,82,20,64,64,64,64,228,202,230,234,216,232,64,122,64,182,186,20,64,64,64,64,204,222,228,64,198,64,210,220,64,232,202,240,232,116,20,64,64,64,64,64,64,64,64,228,202,230,234,216,232,92,194,224,224,202,220,200,80,222,228,200,80,198,82,64,86,64,80,222,228,200,80,198,82,64,74,64,214,202,242,82,82,20,64,64,64,64,64,64,64,64,214,202,242,64,122,64,214,202,242,64,86,64,98,20,64,64,64,64,228,202,232,234,228,220,64,228,202,230,234,216,232] print(decrypt(a)) ``` ![image](https://hackmd.io/_uploads/BkX3jm75C.png) ![image](https://hackmd.io/_uploads/BJcas7Q9A.png) flag: `grodno{xa-xa-xa-terrorist}`