Data and Viral Code Integrity in Maté

The Maté virtual machine is a powerful mechanism for sensor networks, providing execution safety, energy-efficiency through concise programs, and rapid network reprogramming through viral code. Viral code propagation has obvious security issues; a single nefarious program can quickly take over a network, while program conciseness exposes possible weaknesses to cryptanalysis and mote failure means that physical mote compromises can easily go undetected. Data replay attacks can disrupt the results from a network. We present the security mechanisms we have incorporated into Maté to address these problems. We discuss the mechanisms with and without the possibility of mote compromise. We show how the disparate encrypt/decrypt difficulty of RSA can be used for public-key digital signatures, how cut-and-paste attacks can be prevented through version vectors, and data replay can be suppressed. These mechanisms suggest what roles symmetric and asymmetric cryptography can play in a sensor network, indicating what hardware primitives are needed for a sensor network to be secure.