When building advanced electronic systems, outcomes depend on the integrity of the system's internal components. Today, however, counterfeit, subpar, and defective chipsets and circuit boards flood the market. When these counterfeit parts fail, they can sink both a manufacturer's brand equity and its bottom line, cause catastrophic damage to key infrastructure or military systems, or even put lives in danger when applications demand high reliability. To address this problem, Booz Allen Hamilton developed Attacus, a novel solution that quickly determines the authenticity of electronic system components. Attacus is built upon software-defined radio technology that detects weak signal microfluctuations. Using this approach allows us to passively take electromagnetic measurements from components or devices in situ. Attacus takes the guesswork out of integrity authentication by comparing these measurements to trusted signatures, and reveals any deviations in performance or functionality.