Development of an advance nano-satellite VELOX-II on-board computer

Abstract

The objectives of this project are to discuss about the C8051F120 Pumpkin’s board On-Board Computer (OBC) on a Nano-Satellite VELOX-II, highlight the possible encryption techniques that the OBC can utilise, and then design and implement a cryptography cipher to encrypt the data for transmission for satellite application and prevent hackers from eavesdropping on the data. The OBC is responsible for the data handling of the satellite. It stores the data and only sends the data when the ground station requests for it. The cryptography cipher function is programmed into the OBC so the data can be encrypted before transmission. Possible encryption techniques include cryptography algorithm like AES128, RC4, RSA, and key exchange methods like Diffie-Hellman (DH) and Menezes–Qu–Vanstone (MQV). This report also discusses the limitation of the satellite OBC. The results show that AES128 in CTR mode cipher is suitable for the satellite operation and it has a processing time of 2.325 ms per 16 bytes of data. The AES128 in CTR and the key exchange protocol have a code size of 2632 bytes and uses 354 bytes of RAM. The functionalities of the cipher in the micro-controller are demonstrated using a C# client to encrypt and to decrypt message strings as well as to encrypt and decrypt to images. The capabilities of the key exchange protocol based on the cipher are also explain and demonstrated. Lastly, this report also highlights the possible problems and future development of the cipher.