Contents I. Introduction
IoT is a new revolution of the Internet, supporting a stronger connection between objects and humans [1] . There can be smartphones, coffee makers, washing machines, cars and so on using Wi-Fi connection or GPRS. IoT applications are increasing due to the advancement in different fields, especially ubiquitous computing networks. The growth of the IoT will reach multi-billions connected devices in 2020 [2] . With the increase in digital connections between devices, more and more data is collected and data attack is becoming more sophisticated and dangerous than ever before. Attackers exploit risks of IoT devices to steal data and intrude our privacy. Therefore, information security is necessary and the best way to protect information is encoded. Encoding is a data protection method, in order to prevent the thieves from understanding data content. DES (Data Encryption Standard) algorithm is the method in which the encryption key and the decryption key are the same. The block size of the data unit is 64 bits and the length of the key is 64 bits, too. This leads to a huge problem that the key must be accepted by the sender and the receiver because data can be stolen during transmission when the key is detected from one side [3] . Therefore, in order to replace the DES algorithm, the AES algorithm was created as an improvement to the security of information based on DES. Nowadays, the algorithm AES is widely used, so many researches have published various versions of improving AES.
