In this article" , a new adjustment is made on Twofish algorithm based on using a new operation called cyclic group extended # (CGE#) operation for increasing the randomness of algorithm. This is a new operation works on 8-bits and using 30 tables constructed with cyclic group and multiplication in Galois Field (GF) (2 8 ). A new (CGE#) operation is used instead of (X-OR) operation in each round of Feistel of Twofish. This is done by using dual keys: one key is used for selecting one table among 30 tables, and the other key is used for: encryption and decryption. The proposed algorithms are evaluated by using many security metrics such as complexity, NIST, histogram and correlation coefficients. The modification has given good results in these metrics, and this leads to make the proposed algorithm much more robust against many the attacks.