Securing TFTP packet: A preliminary study

With the advent of pervasive computing nowadays, there is a need to deal with security including integrity and confidentiality to maintain the accuracy, and distribute data safely and efficiently. Therefore, it is important to find the best solution for protecting sensitive information through encryption in constrained environment. However, due to the limitation of resources, it is difficult to implement common cryptographic functions on this type of environment. In addition, an ideal encryption algorithm which is suitable for this environment would need to be lightweight. In this paper, a preliminary study on encrypting data is carried out using two lightweight symmetric algorithms, AES and DES. We also identify an experiment of transferring variable size of encrypted data using symmetric encryption, AES which utilizes 256 bits key size. The data is transferred in local network between two computers using TFTP (Trivial File Transfer Protocol). Finally key exchange concept is proposed based on Diffie Hellman Key Exchange (DHKE) which improves the security of TFTP. From the result, it showed that AES is faster to encrypt files although its key size is bigger compared to DES. Besides, it took less time to send normal packet through TFTP compared to encrypted packet as the file size changed after encryption.