HASH MD5 function implementation at 8-bit microcontroller

Microcontroller is often implemented in world manufacturing industry either part of an electronic product, such as a remote terminal unit. Remote terminal unit is an electronic device that responsible for retrieving data using sensors to a server, through cable network or a wireless network. The sensor used to read the data of temperature, altitude, and so on as required. As for the network that used as a medium for data delivery, can be via fibre-optic cable, GPRS modem, VSAT satellite, RF channels, and so on. Problems can occur when the data is sent as a plaintext (not secure). Such data can be read by unauthorized persons in various ways. So it needs to deploy a system of information security that can be implemented into 8-bit microcontroller. This research was conducted on the addition of the function signature, with the purpose of data integrity. Algorithms MD5 implement on 8-bit microcontroller-board, based on Arduino Uno kit. Then the next development stage of this research is, the data sent from a remote terminal units can be encrypted by the microcontroller, using either the algorithms AES, DES, 3DES or TwoFish encryption algorithm, among others. The result of this initial research, MD5 hash algorithm can be implemented in an 8-bit microcontroller with 100% accuracy. But it has some limitations on the issue among them, the data can be processed to a maximum of 15 (fifteen) characters, data input using keypad matrix 4×3, MD5 hash output is displayed on the LCD graphics 128×64 and can only enter data input capital letters only.