Time REsilient System (TRES) uses proprietary algorithms and methodologies to detect, alert and fight through GPS cyber-attacks. These attacks are undetectable by current state-of-the-art technologies that use radio frequency approaches to compare time from different satellite systems, such as the European (Galileo) and Russian (GLONASS) systems. Time synchronization is critical to the operation and maintenance of the electric power infrastructure. In addition to longitude, latitude and altitude, GPS provides a critical fourth measurement—time. GPS has become a vital “invisible utility,” providing precise time information needed by users ranging from the financial and transportation industries to the electrical utility sector. GPS satellites contain atomic clocks that attach very precise time data to GPS signals. As GPS receivers decode these signals, receivers are synched to the atomic clocks. Users can determine the time to within 100 billionths of a second, without the cost of owning and operating atomic clocks. To efficiently transmit and distribute power, energy suppliers use GPS time synchronization to manage electrical grids.