The security system of AES data has been analyzed in this work. The basics of Galue fields, which are related to the mathematical model of the AES algorithm, are also presented in this work. The transformations of The AES algorithm have been analyzed and illustrated with examples. The programmes of the AES algorithm performing these transformations are also presented here. In this piece of paper you will also find some suggestions and their realizations concerning the possibility of the modification of the AES algorithm. Moreover, the restrictions of the key and block of the AES algorithm are submitted. In the last part of the work you will find a program of AES algorithm, as well as sub-keys, S-tables, programs of modified S-tables, and the results of displayed the programs.