Key management and secure software updates in wireless process control environments

Abstract

Process control systems using wireless sensor nodes are large and complex environments built to last for a long time. Cryptographic keys are typically preloaded in the wireless nodes prior to deployment and used for the rest of their lifetime. To reduce the risk of successful cryptanalysis, new keys must be established (rekeying). We have designed a rekeying scheme that provides both backward and forward secrecy.Furthermore, since these nodes are used for extensive periods of time, there is a need to update the software on the nodes. Different types of sensors run different types and versions of software. We therefore establish group keys to update the software on groups of nodes. The software binary is split into fragments to construct a hash chain that is then signed by the network manager. The nodes can thus verify the authenticity and the integrity of the new software binary. We extend this protocol by encrypting the packets with the group key such that only the intended receivers can access the new software binary.

An Efficient Key Distribution Scheme in Wireless Sensor Architecture with Arduino and XBee

“…Nilsson et al [5] presented asymmetric key management for the wireless process control environment. In their design, they proposed a key changing methodology of sensor nodes after a certain period of time.…”

A Security Analysis for Wireless Sensor Mesh Networks in Highly Critical Systems

“…Finally, although WirelessHART offers different mechanisms to prolong the lifetime of sensor nodes (e.g. synchronization for the transmission), it does not guarantee the updating of security credentials during that time period [12], which may be a risk to the security of the system.…”

Mitigating Sandwich Attacks Against a Secure Key Management Scheme in Wireless Sensor Networks for PCS/SCADA

“…In this section, we analyze the performance of our proposal, Alzaid et al's scheme [3], and the similar scheme proposed by Nilsson et al [15]. Our performance analysis covers memory overhead, communication cost, and computation cost for these schemes.…”

“…Nilsson et al [15] proposed a key management scheme for WSN applications in PCS/SCADA environments [4,7,14,16], which was incorrectly claimed to provide future and past key secrecy. Nilsson et al's scheme uses key transport, not key agreement, where the new pairwise key is determined solely by the sensor node.…”