STFTP: Secure TFTP Protocol for Embedded Multi-Agent Systems Communication

Today's embedded systems have evolved into multipurpose devices moving towards an embedded multi-agent system (MAS) infrastructure. With the involvement of MAS in embedded systems, one remaining issues is establishing communication between agents in low computational power and low memory embedded systems without present Embedded Operating System (EOS). One solution is the extension of an outdated Trivial File Transfer Protocol (TFTP). The main advantage of using TFTP in embedded systems is the easy implementation. However, the problem at hand is the overall lack of security mechanisms in TFTP. This paper proposes an extension to the existing TFTP in a form of added security mechanisms: STFTP. The authentication is proposed using Digest Access Authentication process whereas the data encryption can be performed by various cryptographic algorithms. The proposal is experimentally tested using two embedded systems based on micro-controller architecture. Communication is analyzed for authentication, data rate and transfer time versus various data encryption ciphers and files sizes. STFTP results in an expected drop in performance, which is in the range of similar encryption algorithms. The system could be improved by using embedded systems of higher computational power or by the use of hardware encryption modules.