Today, there are many cryptographic algorithms that are designed to maintain the data confidentiality, from these algorithms is AES. In AES-GCM, the key in addition to the IV are used to encrypt the plaintext to obtain the ciphertext instead of just the key in the traditional AES. The Use of the IV with the key in order to gain different ciphertext for the same plaintext that was encrypted more than ones, with the same key. In this paper, the mechanism of change the IV each time in AES-GCM was modified to get more randomness in the ciphertext, thus increase the difficulty of breaking the encrypted text through analysis to obtain the original text. NIST statistical function were used to measure the randomness ratio in the encrypted text before and after modification, where there was a clear rise in the randomness ratio in the encoded text which obtained by using the modified algorithm against ciphertext by using the normal AES_GCM.