A method and circuit for an Automatic Self Checking and Healing (ASCH) of Physically Unclonable Functions (PUFs), the method includes: controlling a skew input added to each PUF cell of a PUF array in a circuit with sub-mV resolution; healing a portion of unstable bits of each PUF cells locally; and performing a second self-checking on healed PUF cells to determine final PUF cells to discard. The method further includes performing at least one of a static operation mode, a dynamic operation mode, and a hybrid operation mode of ASCH stabilization system based on design needs to reconfigure and mask the PUF array to achieve less than 1E-8 Bit Error Rate (BER) with less than 25% masking ratio. The circuit includes the skew input, a self-checking controller, a high-speed readout, a validity detector, and a Digital-to-Analog Converter (DAC). Further, each PUF cell in the PUF array is an inverter-based PUF and includes a first stage inverter and a second stage inverter such that the second stage inverter includes other stages except the first stage inverter.