PETRA: a secure and energy-efficient software update protocol for severely-constrained network devices

Abstract

In this paper we propose PETRA; an energy-efficient and secure software update protocol for severely-constrained network devices. PETRA ensures the authenticity and end-to-end integrity of software update components delivered from trusted content distribution networks. The protocol operates by employing a set of energy-efficient data structures and cryptographic constructs to efficiently detect any form of man-in-the-middle modification attacks on the update packets. This methodology contributes to a sizeable decrease in network traffic and as a result huge energy savings. This makes PETRA a very suitable security protocol for limited-resource battery-operated devices such as low-end mobile phones, wireless sensors, and even Radio Frequency Identification Devices (RFIDs) tags. Moreover, PETRA realizes an incremental security verification mechanism that allows the dynamic eager loading of received software components. This mechanism prevents any form of service disruption or operation downtime during the code upgrade process. A prototype PETRA implementation is tested on a grid of simulated micaz sensor nodes running the TinyOS operating system. A platform-independent performance analysis and an experimental simulation show that PETRA can achieve up to 30% average reduction in network-wide energy consumption.