Empirical Development of a Trusted Sensing Base for Power System Infrastructures The transition from traditional power systems into smart grid infrastructures constitutes secure data acquisition to prevent widely explored false data injection attacks. In this paper, we design, implement, and deploy a trusted sensing base (TSB) that enhances the security capabilities of traditional commodity power system sensors via enabling them to encrypt analog ac signals at data acquisition points. Nowadays, data encryption occurs at phasor measurement units (PMUs) after the measurements are sampled and digitalized at the analog-to-digital devices. Through pushing the encryption to within the sensors, TSB reduces the size of trusted computing base for the whole smartgrid infrastructure and hence increases its trustworthiness. We have developed a hardware working prototype of TSB in a real-world power system test-bed, including PMUs and energy management systems. Results are very promising for practical real-world deployments. TSB encrypts analog signals on the sensor side and retrieves a very accurate estimate of them on the global positioning system-synchronized control center side with minimal latency.