Given the rapid advancement of data innovation and the massive volume of data exchanged over the Internet, which needs protection from electronic theft and extortion, there are many encryption algorithms that developed to protect data. Development in the field of coding (Cryptography) has always been accompanied by a development in the field of decoding and Cryptanalysis. This led to the Weakness of many encryption algorithms. Therefore, the need to develop a new methods are necessary. In this paper, a method based on geometric series for encrypting data was proposed, where two keys are used, the amount of the incremental in sequence represents the first key; the number of terms in the sequence represents the second key. The proposed model has been tested using a number of appropriate attack techniques; the proposed model has proved its efficiency and strength against attacks several technique of attacks are applying on the propose model, the results proved that the strength of the proposed method. As a contribution, this paper using a sequence to concatenate the values of the sequence terms to hide the origin character ASCII code which adds fuzzy cryptography to guess the correct ASCII code.