Security Device Including Physical Unclonable Function Cells, Operation Method of Security Device, and Operation Method of Physical Unclonable Function Cell Device

An operation method of a security device including a physical unclonable function (PUF) device, the method comprising:

• selecting a first target PUF cell based on valid information;
• applying a first voltage to a first word line connected with the first target PUF cell;
• generating a first target value based on a first target current corresponding to the first target PUF cell and generating a first central value based on a sum of first currents output from first PUF cells, connected with the first word line, of the plurality of PUF cells;
• determining a first target bit of the first target PUF cell based on the first target value and the first central value;
• and
• generating a security key based on the first target bit for responding to an authentication request,
• wherein the valid information is generated by:
• generating a plurality of sensing values and a plurality of central values from a plurality of PUF cells connected to the first word line;
• comparing a plurality of sensing values and a plurality of central values, respectively;
• and
• storing an address corresponding a valid PUF cell based on a result of the comparison.

An operation method of a security device including a physical unclonable function (PUF) device and a controller configured to the PUF device, the method comprising:

• applying the first voltage to the first word line;
• generating a plurality of sensing values and a plurality of central values from a plurality of PUF cells connected to the first word line;
• deciding whether each of the plurality of PUF cells is a valid PUF cell based on the plurality of sensing values and the plurality of central values;
• and
• storing addresses corresponding PUF cells, which are decided as the valid PUF cell, in a memory of the controller.