able 4.1 Arithmetic modulo 8 +01 0 123 55670 234567 4 5 6 223456701 334567012 5670123 234 667012345 770123456 0 (a) Addition modulo 8 3 5 0 01234567 000000000 101234567 202460246 614725 404040404 5274 163 606420642 w01234567 65432 mfy@ustc. ed (b) Multiplication modulo 8 (c)Additive and multiplicative 15/55 inverses modulo 8mfy@ustc.edu.cn 现代密码学理论与实践 15/55