Apparatus for generating secret information on basis of ring oscillator architecture and method of same

An apparatus for generating secret information on the basis of a ring oscillator, the apparatus comprising:

• multiple hardware physically unclonable function (PUF) information generation units each including at least one ring oscillator cell configured to generate PUF information;
• a phase checking unit configured to
• cross-check phases for multiple pieces of the PUF information that are output from the multiple PUF information generation units, respectively, and
• detect a phase of a clock signal generated through each of the at least one ring oscillator cell;
• and
• a secret key generation unit configured to output secret key information based on a result of comparing the multiple phases received from the phase checking unit;
• wherein the at least one ring oscillator cell comprises:
• a flip-flop element configured to receive an oscillator enable signal and a system clock signal;
• an AND gate;
• an odd number of inverter cells connected to an output terminal of the AND gate in series;
• and
• a divider configured to divide a clock of a last inverter cell of the odd number of inverter cells by two,
• wherein an output of the flip-flop element is connected to a first input of the AND gate, and
• an output of the last inverter cell is connected to a second input of the AND gate;
• and
• wherein the phase checking unit and the secret key generating unit are integrated in a hardware component.