Power Fingerprinting (PFP) provides an innovative, powerful integrity assessment tool that is particularly well suited for critical embedded systems, including resource-constrained and legacy platforms such as those still being used by energy providers. One of the main applications of PFP is cyber security monitoring of critical systems and the detection of malicious intrusions, tampering, and attacks. Among the advantages of PFP over other intrusion detection tools, is the ability to detect zero-day and targeted attacks while introducing almost negligible overhead on the system being monitored. In addition, it can be applied independent of the system hardware, operating system, and software application. For these reasons, PFP has the potential to play a key role in Smart Grid cyber security by protecting platforms and systems that are not covered by traditional security approaches, such as antivirus systems.