Compression and encryption of self-test programs for wireless sensor network nodes

This paper considers the in-system testing of wireless sensor network (WSN) nodes that operate with strict limits on energy and cost, and are prone to malicious interference. We show that while performing testing using software-based self-test (SBST) programs has clear advantages, node energy efficiency can be increased by compressing self-test programs before distributing them over the wireless interface. We demonstrate a node energy savings by using an adaptive test program compression scheme with a small memory footprint based upon the BSTW algorithm in conjunction with Golomb-Rice coding. As well, we assist in providing security during the testing process by offloading cryptographic functions to hardware for a measure of protection against malicious interference during testing.